Are you in the habit of giving gifts to people who don’t know you?
A Chassan to his Kallah? They don’t know each other (as much as they think they do!)
Anyhow, you could tell her as you’re giving it.
If you tell her, great! My problem would be giving fake and allowing her to think it’s real.
popa said it very well:
If anyone gave me fake jewelery without telling me, it would completely negate all the good will from the gift when I eventually found out.
SiDi™