אתה אח ברוך הבא
I believe this is how you would write it according to Google Translate but I can't read it aloud... luckily, so many people learn Hebrew for religion that a pronunciation key is not hard to find on-line (it's read from right to left). Most christian pastors who attended a seminary had to learn the Ancient Hebrew and some form of Ancient Greek in their studies because The Bible is written in Hebrew (Old Testament) and Greek (New Testament)
My father knows the old Hebrew but I don't know if he could tell you how they say it now in Israel
"What if your Welcome" cannot be translated into Hebrew, because "your welcome" in Hebrew is literally "blessed is he/she who comes" You can say, "what if it happens that you are permitted to enter" = ma yikreh im mutar lekha/lakh lehikanes.
welcome in Hebrew is "baroch haba" or "shalom" or "brocim habaim"
brukhim haba'im le'amritsar
sister and brother = achot veh ach (รยรโรโขรยช รโขรยรโ)
You say, "Bendiciones, hermano."
atah akhi? (אתה אחי)
ha'ah hanotzri sheli
"Brother of" and "brother" are written and pronounced the same: ach (אח) (ch is a gutteral sound)
Bienvenido, hermanote / carnalote
Baruch Haba Le'olami - ברוך הבא לעולמי
my big brother = achí ha gadól (אחי הגדול)
If you are responding to "Thank you," you would say bevakasha (בבקשה) to anyone.If you are indicating that someone is welcome [in your home, etc.], you would say brucha haba'a (ברוכה הבאה) to a female.