Una, you would totally rock the floral jeans. I don't see them as necessarily being for younger gals, either. A lot would depend on the type of floral. (I hope age-appropriate dressing doesn't mean boring, because I'm going to choose mutton dressed as lamb over boring...)
I prefer the ASOS print over the Anthropologie pants, but that largely has to do with the crotch flower issue mentioned above. Also, for a trend you're not 100% sure about but want to try, then the less expensive pair might be more palatable.