hi
i agree with pp, it sounds like you should try to slowly extend her A time. start with the first A time, aim for 1.5 hours to start and see if this gives you a long nap. try it for 3 days and if still no long naps then extend by another 10 min. keep the rest of your A times the same, if you're getting a short nap the following A time has to be shorter because a short nap is not as restful and you don't want them to be OT. but at 4 mo she should be close to being able to do 2 hours A time (if she's having long naps that is). the first a time should be close to 2 hours so that is what you're aiming for...just do it slowly to avoid OT.
at 4 mo usually LOs are close to being able to do 2 hours A time and switch to a 4 hour EASY routine around this age. some a bit earlier and some a bit later. we were about 4.5 mo. when we switched finally to 4 hour EASY, before this she couldn't tolerate 2 hours A time. i notice your E times are not consistent. at 4 mo she should be able to go 4 hours between feeds. the short naps may throw it off a bit, but this is what you are aiming for, definitely not longer than 4 hours between feeds. at 4 mo they do 2 long naps and a catnap.
4 hour EASY
6:30 awake and E
8:30-10:30 S
10:30 E
12:30-2:30 S
2:30 E
4:30-5:15 S
6:30 E
6:45 or 7 bedtime
10 df
oops...nicole and i were typing at the same time, but same advice!