Toddler question. Help!

Dr
Ok so I know this isn't controversial really but I need as many ideas as possiable because I can garuntee I've already tried over half lol I apologize for posting in the wrong room but I need your help. 
My toddler wont let me brush her hair. The brush outs are a daily (or semi daily) battle that always results in my husband or mother in law holding her down while I brush while she fails around screaming her head off. It's been like this ever since her hair started getting longer and she's now three. It seems to be getting worse as she's starting to get upset AND mad about it.
I have tried other solutions, I've tried distraction techniques, I've tried to make it really fun, I use a detangler, I use an adult conditioner, I've kept it in braids (it only ends up frizzing and making little knots in her hair), I've chased her around the house to make a game of it, Ive tried to let her flail around while I brush but that just dies more harm then good, I've talked to her about cutting it, I put it in a pony tail practically everyday, I have gotten a fun cute brush, I'm out of ideas!!! NOTHING works, she doesn't seem to understand when we explain why it needs brushed (or doesn't care) and won't answer any questions. We haven't cut it yet because she's has stranger anxiety and I'm afraid she won't allow a stranger to touch her hair. It makes me sad because I love her long beautiful hair. 
You guys I really don't know what to do anymore. ;( leaving it unbrushed is not an option because it gets to be a nasty mess on the top of her head within 48 hours. Baths everyday don't fix the knots, it has to be brushed. Ugh! I'm so frustrated! Any ideas? Help!