Ah, this happened a lot with DS on and off. Funnily enough, he asked me to feed him this morning (he turned 7 on Friday)! Actually, he was watching a documentary on baby tigers in captivity who are fed by people when their moms won't care for them... he was wishing to understand their experience.
At any rate, if I could go back and do one thing over when DS was smaller, it would to be to totally relax about anything regressive, just don't sweat it. In general, I came around to that way of thinking when DS would want me to feed him, or need to nurse more after a time when he didn't need it so much, etc. I just wish I hadn't gone through the "freaked out" phase first and just totally relaxed and went with it from the start. Usually, they just need that "you'll be there no matter what" reassurance and once the need is met, they can move on.
As to it not passing, it could be she understands that there is some stress involved with this behavior. Particularly if you and DH are taking different approaches. That alone could be enough to fuel the behavior, and keeping her hanging onto it. Kids are so perceptive! Relax and go with it with NO stress or questions and it will likey pass. Kids do go through phases of regression and it's entirely normal. If their needs are met, and their attachment is in order, they also go through the normal stages of maturation, not the least of which is wanting to do for themselves... the thinking on this is if you "do for them" they'll never do for themselves but I just have no evidence that this is true. However, I do have experience with the opposite. The more I resisted, the more I fueled DS's anxieties and arrested the maturation process. The more the behavior persisted. That is just a fact of my own experience of course. I can't speak for everyone but more and more I beginning to see that most things are that way: completely opposite from how our culture would like you to believe. *sigh*
I'd tell DH to relax and enjoy it. DH actually LIKES feeding DS, he NEVER balked and I believe he fed him much longer than I did. There is something very comforting about a parent feeding a child. DS generally eats on his own now unless I share some of my chocolate with him as a surprise and pop it into his mouth!

THe best and hang in there!
Em