妹 is the kanji for little sister with different readings and usages.
Most frequent readings of it are 'imouto' (kun-yomi=Japanese reading) and 'mai' (on-yomi=Chinese reading).
愚妹 (gumai) and 妹 (imouto) are humble ways of saying little sister, used when little sister is your own or very familiar to you like a childhood friend, etc.
I haven't come across a uniquely "cute" way of saying little sister but you can add -san to make it respectful or -chan to make it friendly or somewhat cute.
Closest I can get you to it is with adding a little friendlier intonation to it, also adding 'yo' if you are calling to your little sister or close younger female friend; Like 'imouto-chan yo..!'
The sentence 'I love my sister' would be 姉が大好きです (ane ga daisuki desu) in Japanese when talking about one's older sister. To say 'I love my sister' when referring to a younger sister, you would say 妹が大好きです (imouto ga daisuki desu).
You could say futago no shimai, but the word for sister (or brother) would depend on whether you are talking about an older sister (onesan) or a younger one (imoto), and that goes for twins too, so you always know which one was born first. Futago is twin.
'Your little sister' in spanish is written and pronounced 'Tu hermana pequena'.
hiko
chisai kitsune
You may say 'imouto.'
The term 'little sister' could be translated as 'imouto', to say 'my little sister' you could say 'watashi no imouto'. But remember, if you are going to refer to someone else's little sister, you must say 'imouto-san', 'san' being the honorific, which are a key element of the Japanese language and etiquette.
You may say 'imouto.'
I-mo-u-to いもうと
Imooto (いもうと, pronounced "ee-moe-toe", with emphasis on the "mo") means little sister. Add -san to the end of imooto when it is someone else's little sister.妹Imouto
To say "little sister" in Cherokee, you would say "adalisdi" for little and "unega" for sister. So together it would be "adalisdi unega."
zan zumi
Russian for "little sister" (meaning younger sister) is младшая сестра (pronounced MLATshaya seeSTRA).
munting kapatid
The sentence 'I love my sister' would be 姉が大好きです (ane ga daisuki desu) in Japanese when talking about one's older sister. To say 'I love my sister' when referring to a younger sister, you would say 妹が大好きです (imouto ga daisuki desu).
Little sister is addressed depending on the order of her birth: the eldest sister - ate second sister to the eldest sister - ditse third sister to the eldest sister - sanse the youngest - bunso
小妹妹= Little Sister 小=Little 妹妹= Sister Xiao Mae Mae (may may)