Those "ouchless" brushes are a joke, at least IME. A good straight comb or pick is what's worked best for my girls' fine & curly hair during toddlerhood. I repeat the suggestion to comb it while the conditioner is still in, or half-rinsed. I haven't had trouble with any of the kid-oriented leave-in spray detanglers leaving an oily residue... anyone else?
If her hair just can't handle most conditioners without greasing up, though, you might try some of the more organically crafted shampoos & conditioners. I really like Avalon Organics lavender scent hair products. They also have the bonus of calming, relaxing aromatherapy for the child (and mother too!) just before bedtime. This product in particular was very mild and the conditioner very light. My current fave though is Nature's Gate "original" blend with this lovely, very heady & warm myrrh scent (among many others). It's delicious. It's the first shampoo I've found that I can use on my oldest dd's greasy teenager hair, dd2's DRY frizzy flyaway hair, dd3's fine, silky (but flyaway) locks, and dd4's fine, dry, curly hair. Mine, too, which is currently a mixture of all of theirs-- fine, curly, flyaway. They all, unfortunately, inherited my unruly hair, in one form or another.
My dd3 has an incredibly tender head. Honestly, it aggravates me because I can't possibly be any gentler with her.
I make her sit and get her hair combed while she's still dripping in her towel. She's never happy about it, but as soon as I say "it'll tangle up if you let it dry without combing..." she changes her tune and sits down. I try to braid it if I possibly can, although that's kind of hit or miss these days, just due to bedtime bedlam. Dd4, who is a few months shy of 3y/o, sits through getting her hair french braided better than her 5y/o sister, though. Ugh.
Oh-- one more tip-- distraction. A favorite video/DVD could be brought out only for hair-combing time, to keep her fixated on something other than her hair. That's been a big one for us over the years.