Thank you everyone! I will try to get different (better?) pads for diamondback bike. Pads adjusted OK, Wiped all with alcohol, wheels trued. Pads seems to be hard/dry (is it possible??)
For wife I just ordered
Save up to 60% off new Cafe Bikes | Hybrid Bikes Cafe Latte Disc 2014 and bought pair of pedals of Amazon for $9. Shimano Alfine looks very cool, but I didn't find anything in my price range (~$500) I think we will be OK for now and later I can add Shimano Alfine if gearing going to be a problem, and, MOST importantly, those bikes will be used enough to justify upgrades.