WOHMs--talk to me about weekend naps!

Our LO naps like a champ at her sitter's house during the week--usually two 1.5-2 hour naps daily. (She's 7 months old.) On the weekends, though, we're lucky if we get two 45-minute naps out of her. We put her in her crib and she screams and screams. If she DOES go to sleep, she always wakes after that first sleep cycle. We try to stay home at least through her first nap, before we start running errands/being out and about. Any tips for making her weekend naps consistent and not totally crappy? Would nap training just for the weekend even work?

Night sleep is not affected by her naps at this time, so we just really need help with the naps!