Hi there.
Sorry to hear you are having some difficulty with naps at the moment.
Did the short naps start when you increased her A to 2hrs?
Is anything else going on that might be disrupting her sleep, teething? reflux?
It sounds like she is OT although the A is good for her age. Have you started any new baby groups or anything like that? More visitors to the house perhaps? If not OT she could be OS. Or it could be developmental. Generally if the A time is ok then you would need to look around for other reasons for sleep disturbance to see if it is anything you can control. LOs naps tend to improve around the 6 month mark.
You could try to extend the nap with W2S (wake to sleep)
http://babywhispererforums.com/index.php?topic=223809.0This can help to extend the nap. You do it for 3 days and stop on day 4 to see if she is transitioning alone, if not use W2S again day 5,6,7 and again hold of day 8 to see if she can transition. Some people have success with this.
You might want to set yourself a limit to how much you attempt to extend as it can be quite tiring and even stressful. Maybe just try one nap each day (the same one each day, I recommend the first one as you can get a better afternoon if the firs nap is longer), and you might limit your attempt to 20 mins. It is up to you.
If you choose not to extend or if LO doesn't re-settle then get her up and get on with the day. Reduce her next A time a little (say 10 mins less) to avoid OT. you might also need to add more naps into the day to see you through to bed time. At 4 - 5 months we had 5 naps per day as they were short!
EAS timings. You need to track the A from when she wakes, not when she feeds so that you don't accidentally give her a really long A time. Track the E time separately and keep feeds as regular as possible at the 4hr mark. It is fine for your EASY to be EASAEAS. Short naps can throw the routine off so if you see an E and an S about to clash then you might feed a little earlier than the 4hrs so that she can feed, have a minute or two awake after the feed and then be put down for the nap.
hope this helps