Hi!
Your ped is right about holding off on lunch - milk (whether formula or breastmilk) has far more calories/fat/nutrients than any solid food and is definitely better to help gain weight. And it seems like what you're doing is working! Your dd gained more than 1.5pounds in only 1 month! And I wouldn't worry about the night feed, it's normal for breastfed babies to still need a feed at this age. So try not to stress too much, you're clearly on the right track
Keep that in mind when you read the rest of this!
As far as her taking small quantities of milk, the best solution I have for that really is moving towards a 4h EASY. It seems counter intuitive, to feed less often but take more, but it actually does work. For example,
3h EASY 4h EASY
7am 4oz 7am 6oz
10am 4oz 11am 6oz
1pm 4oz 3pm 6oz
4pm 4oz 7pm 6oz
7pm 4oz
Total 20oz Total 24oz
When you say that you've tried many times to go to the 4h EASY, how have you gone about it? Have you jumped right to 4h intervals, or do you try to make the change gradually? How long did you try 4h intervals before going back to feeding more frequently? I ask because when you make the change more gradually, it allows her time to get used to taking larger amounts less frequently. She won't jump from 4oz to 6oz per feed right away, but if you change gradually and keep it up for a few days to a week then her consumption will likely increase.
Here are the guidelines for milk consumption:
http://babywhispererforums.com/index.php?topic=67933.0 (even though the title says formula, it applies to the total milk consumed, including breast. And don't forget that all milk added to solids counts towards total milk intake too!)
hth!