We went a trip to visit our families when my son was 3 1/2 months old. We were trying to extend to the 4 hr easy. I found that with all the extra activity and people wanting to play with him and hold him, he just couldn't stay awake as long as he could at home. He pretty much followed the 3 hr EASY while there, then when we got back home, we started working toward 4 hr EASY again. I think it just depends on your lo. I guess just be flexible to go either way, depending on how she handles the vacation.