When you say Gaelic, I can only assist with the version spoken in
I was taught Irish(Gaelic) at school but where I lived it was only a
second language, ( there are areas in Ireland where it is the
primary language), needless to say the phrase "I love You" didn't
crop up too often in Irish classes. So just to be on the safe side I
made a call to Coiste Tearmaiochta An Foras na Gaeilge, which is a
government agency who are the authority on standardized Irish
terminology. They have reliably informed me that the proper way to
say "I Love You" in Irish is "Ta Gra Agam Ort" phonetically this
would be "thaw graw ah-gum uh-rt".
The name Dawn is an old English name and doesn't have a direct
translation into Irish, she would simply be known as Dawn.
Hope this helps,