IANAL - It's always upsetting to see the 'idea-guys' knock the engineers, so here are my $0.02. So who owns the IP? If you haven't created a legal entity where

IANAL - It's always upsetting to see the 'idea-guys' knock the engineers, so here are my $0.02. So who owns the IP? If you haven't created a legal entity where you have signed over the IP, then I think technically it is yours, or at least 50% yours. If that's the case, signing something like this seems a little shady. If you call her your co-creator, that implies you are part of the creation process, and if that's the case, I feel that signing this may not be the best idea. Additionally, I always think people should have the difficult conversations first, and I think by not signing this, it's not like you are <em>fucking</em> her over, but instead laying out a difficult conversation on the table. I think all founders should be comfortable having conversations in the beginning about equity, and if she isn't comfortable with that, remember that you are part of the reason the product exists to begin with. On the other hand, if you want to give it, I agree with ggchappell -> it sounds like you're giving her a gift. Yet there is still no reason to sign something like this. I don't see the signing of this document helping you in any way, but hey - IANAL.