My first thought is, this is a business expense for her. Also, unless youre an interior (or exterior) designer, how would you know what to pick? She might have a vision. Did you match her color scheme? Stuff like that. OTOH, if she "likes you" likes you, then it would be cute. OTOOH, shes a business owner and youre kinda saying that you being a GUY makes you an expert to decide what kind of plant she should put outside.

Sigh. This is why i have no friends and i never leave the house.