If the bearer is from an English speaking family, it's up to her and her family how
Aimee is pronounced. Usually, English speaking Aimees in the US will tell other English speakers to say AY-mee. All the Aimees I've ever known do (I'm in the US). Among French speakers they'd almost certainly say it the French way. I knew a bilingual
Aimee who used the accent and the French pronunciation among her French relatives, but asked her friends at school to call her AY-mee.
So if you want to use the spelling
Aimee and the pronunciation AY-mee, in the US that'd be conventional.
- mirfak