Can Prevacid work this quick?

Delia had her first Prevacid dose Thursday, and she’s on a low dose–7.5 mg 1xday. Thursday was horrible for us as she has a cold, Thursday night was terrible, as usual, Friday morning sucked…then she slept Friday afternoon. For 2.5 hours. Straight. She woke up a completely different baby. Friday night she slept! A 4 hour stretch! Saturday she was amazing! Smiley and happy and sweet and accepting of other people. And I felt like I could conquer the world from all the sleep I got! Saturday night–slept again! I felt AMAZING and so did she! We had a family Christmas party last night (Sunday) and she let other people hold her and she was happy and cute and charming and yeah. She’s a totally different baby. Could it be the Prevacid working already, or is it too soon? The dr said it could take up to 2 weeks for the medication to fully affect her. It’s just that she’s on such a small dose and it’s only been 4 days.