Annsa, you want to aim at 4hr EASY and have her nap at around 9am, 1pm and then a catnap say anywhere between 4-5pm. I think the long morning nap may have something to do with her not sleeping well in the afternoon. Try not letting her sleep so long in the morning, waking her up after 1.5 hrs and then try putting her down for another nap close to 1pm. She might be a little cranky but within a few days should adjust. Have you tried w2s to extend her nap? My lo went through a phase where her 1st nap was great but she was stuck on 45 mins for the afternoon nap and was extremely cranky and wouldn't eat well either. I extended her A time and also did w2s and she sleeps well in the afternoon now.
So, if she wakes at 7am, your day would look more or less like this:
7am - awake
E 7.00 - bottle (give solids if you were told to 1hr after milk feed)
A 7.00 - 9.00 (start windown around 8:45, depending on your lo)
S 9.00 - 10.30
Y
E 11.00 - bottle (give solids after 1hr of milk feed)
A 11.00 - 13.00 (start windown 15 mins before, depending on your lo
S 13.00 - 14.30
Y
E 15.00 - bottle (solids 1hr after milk feed)
A 15.00 - 17.00
S 17.00 - 17.45 (start windown 15 mins before nap starts)
A - bath, bedtime routine
E - bottle before bed
S - 19:00
Might wake up at night for more feeds
You said that she was on 4hr easy before, so she might be ok with those A times but if not, start with 3.5 and then move onto 4hr. I put my lo to bed 15 mins earlier for every nap as a part of windown but otherwise thats what her day was like at around 5 months (well thats what we aimed for). It she's not eating well in the morning because she had a feed at 5am, then try watering down that feed or maybe offer her less so that she is hungry enough for the morning.
Also those nap times are not set. Mine will go down for her 2nd nap anywhere b/n 12.30-1pm, depending when she shows tired signs. But I would limit her 1st nap cause I think that might be another reason why she is not taking a longer pm nap.
HTH
Layla