If it were me I wouldn't take too much notice of the MCN and just keep doing what you're doing.
My DS is also three months old and he stills feeds every three hours during the day. There's no way in hell he'd cop it if I tried to stretch him out to 4 - and it's not worth it to me for him to be distressed and me to be distressed by his crying if I tried to do that. I don't mind feeding him every three hours during the day - it's not waking me up or anything so why not?
As far as nights go, he feeds at about 6.30pm before going to bed, wakes around 1am for another feed, and then again around 5/6am so he is only waking once a night. That said he does have nights where he'll wake two or three times for a couple of nights in a row every two weeks or so. Perhaps you could try doing a "dream feed" at around 10 or 11pm before you go to bed to see if that will help cut down the night wakings. Basically this involves putting bub on the boob asleep for late night feed, you don't wake them up or change them or anything. Some babies will attach and go for this, others won't. Unfortunately mine won't,but I've heard it works for alot of people.

Bedding - have you tried wrapping her rather than putting her under blankets? My bub finds wrapping a bit harder to get out of. Or there are also sleeping bag things you can buy that have armholes the baby wears so they remain covered.