12 weeks may be a little early for a 4 hour EASY...Tracey recommends a 3hour cycle until 4 months. I`d be tempted to feed a little more often during the day...which is easy to do if she`s only napping for 45 minutes only anyway. also at 3 months there`s a growth spurt, so she may be hungry all the time for a few days...it`s important to feed her whenever she needs it during the growth spurt...she may be eating every couple of hours and more than usual at night...don`t worry if it is a growth spurt then things will settle down in a few days, but like I say i`d be tempted to then do a 3 hour EASY not 4 so she gets more calories in during the day. 45minute naps happen for all babies at various stages...i think it`s a developmental thing. you can try to extend her naps, or feed when she wakes up to make the EASY cycles more like 2/2.5 hours or do EASAE, whatever feels best to you. good luck...you will get more sleep soon. going 7.30 - 7.30 with just one feed is doing really well for her age, so you`re on the right track.