Lovableness is the noun form for the adjective lovable.

Though no specific, official date is given, I like to believe her birthday is May 13th or at least sometime in May since it's a time when it's warm enough to be running barefoot but not sweltering hot. Another reason I like to believe this is because the birthflower for May is a lily like the magic golden flower that gave Rapunzel's hair healing powers and took up the majority of her wedding bouquet in the Disney short Tangled Ever After. I've also read that sunflowers are sometimes considered a birthflower for May, which I find coincidental since the magic golden flower grew from a drop of sun. Also, the birthstone for May is an emerald like Rapunzel's large green eyes and mean success in love, which she had with Flynn/Eugene. If we want to get into the horoscope, pseudoscientific branch of the subject, children born in May are supposedly motivated, beautiful physically and mentally, understanding, artistic and high spirited dreamers who love to travel. If she was born on May 13th, that would make her a Taurus, whose characteristics include determination, generosity, affection, creativity, cleverness, patience, warm-heartedness, dependability, and being good-natured. One more point in the pseudoscientific horoscope area for the specific date mentioned, as published in this quite interesting "Fortune-Telling Birthday Book" published by Chronicle Books, characteristics of those born on May 13th are honesty, sincerity, intellect, occasionally moodiness, usual kindness and lovableness, and fond of traveling and self-improving opportunities. So though no official birthdate has been given, I believe I've given enough to proof to say that she was at least born in May :)

abusiveness, adaptedness, adverseness, agelessness, aimlessness, airlessness, airsickness, amativeness, amiableness, amorousness, amusingness, ancientness, animateness, anxiousness, arduousness, artlessness, assuredness, austereness, averageness, awesomeness, awkwardness, balefulness, bashfulness, beardedness, bearishness, beastliness, belatedness, betweenness, biliousness, bindingness, bizarreness, blessedness, bookishness, boorishness, boundedness, breathiness, brittleness, brusqueness, brutishness, bullishness, caddishness, callousness, capableness, carefulness, cleanliness, coltishness, compactness, complexness, conciseness, copiousness, cordialness, correctness, corruptness, costiveness, courtliness, crabbedness, crookedness, crowdedness, crumbliness, crunchiness, cultishness, cunningness, curableness, curiousness, currentness, cursiveness, cursoriness, darlingness, decidedness, deviousness, devotedness, diffuseness, distantness, diverseness, dividedness, doggishness, dolefulness, dollishness, doltishness, donnishness, doughtiness, drunkenness, dubiousness, durableness, dutifulness, earnestness, earthliness, elderliness, elusiveness, emulousness, endlessness, enviousness, equableness, erosiveness, eternalness, ethicalness, evasiveness, extremeness, factualness, faddishness, fatefulness, fatuousness, fearfulness, feelingness, fertileness, festiveness, fictiveness, fidgetiness, finicalness, finickiness, fittingness, flightiness, floweriness, folkishness, foolishness, foppishness, foreignness, foreverness, forgiveness, forlornness, forwardness, franticness, fretfulness, frowardness, fulsomeness, furtiveness, gainfulness, gaseousness, gawkishness, genericness, genteelness, genuineness, ghastliness, ghostliness, girlishness, glaringness, gleefulness, godlessness, godlikeness, gracileness, gradualness, graphicness, gristliness, grouchiness, growthiness, guardedness, gutlessness, haggardness, haplessness, harmfulness, hatefulness, haughtiness, hawkishness, healthiness, heedfulness, heinousness, hellishness, helpfulness, hideousness, hirsuteness, hoggishness, hopefulness, hurriedness, hurtfulness, ignobleness, immenseness, inexactness, ingrownness, inhumanness, initialness, instantness, intenseness, irksomeness, jealousness, jitteriness, joblessness, jointedness, joylessness, knowingness, laggardness, languidness, lastingness, lawlessness, learnedness, lengthiness, liberalness, likableness, liltingness, limitedness, lissomeness, literalness, livableness, logicalness, losableness, loutishness, lovableness, lumpishness, lustfulness, lyricalness, mannishness, marchioness, massiveness, mawkishness, mindfulness, miserliness, movableness, mundaneness, naturalness, naughtiness, needfulness, nervousness, neutralness, noisomeness, nonbusiness, notableness, nothingness, noxiousness, obliqueness, obscureness, obviousness, odorousness, ominousness, onerousness, ongoingness, operoseness, orderliness, outwardness, painfulness, passiveness, paunchiness, peevishness, pensiveness, pepperiness, perfectness, pettishness, piggishness, pinkishness, piquantness, piteousness, pitifulness, playfulness, pliableness, pointedness, pompousness, potableness, preachiness, preciseness, presentness, prickliness, privateness, profaneness, profuseness, prudishness, puckishness, pushfulness, queenliness, radicalness, raffishness, raucousness, raunchiness, raylessness, reddishness, relatedness, relaxedness, repleteness, restfulness, restiveness, retiredness, riotousness, roguishness, roundedness, ruinousness, ruthfulness, ruttishness, saintliness, saplessness, scrappiness, scrawniness, scruffiness, seasickness, selfishness, seriousness, serriedness, servileness, sexlessness, shadowiness, shallowness, shapeliness, sickishness, sightliness, silveriness, sincereness, sinlessness, sinuousness, sizableness, sketchiness, slavishness, slenderness, slouchiness, songfulness, sottishness, soulfulness, specialness, splashiness, springiness, squalidness, squashiness, squishiness, starchiness, stateliness, staunchness, stiltedness, strangeness, streakiness, stringiness, studiedness, stuntedness, stylishness, suasiveness, subacidness, sublimeness, subtileness, supremeness, swarthiness, swinishness, tactfulness, tearfulness, tediousness, teemingness, tenableness, tenuousness, thirstiness, threadiness, thriftiness, throatiness, toplessness, tricksiness, tunableness, tunefulness, typicalness, unawareness, uncanniness, uncleanness, uncouthness, ungodliness, unhandiness, unhappiness, uniformness, unluckiness, unmanliness, unquietness, unreadiness, unsoundness, unusualness, uprightness, uptightness, uselessness, vacuousness, valiantness, variousness, verboseness, viciousness, viscousness, visibleness, voguishness, volubleness, waggishness, wakefulness, waspishness, waywardness, wealthiness, weightiness, welcomeness, willfulness, willingness, wimpishness, winsomeness, wishfulness, wistfulness, witlessness, wolfishness, womanliness, worldliness, zealousness, zestfulness