We're leaving my 2.5 year olds hair alone. His hair is silky and wavy though so you can't tell that we don't own brushes. He's unfortunate though in that everyone wants to touch his hair so it never gets a chance to knot up.
Explain to your husband that letting her hair dread isn't "Doing something" to her. Forcing her to have her hair combed IS and she obviously hates it. Why force her to endure something she doesn't have to? There's no reason for her to not have dreadlocks other than the opinions of other people and you know what? Other people are stupid as hell.
He loves his little girl right? He wants her to be happy as she can be? So why would he want to force her to do something that has no real benefit to her and only causes her pain? Dreadlocks are a legitimate hair style. Famous people, doctors, lawyers, people of all walks and ages have them so why shouldn't she? Especially if it will make her life easier?
He needs to focus on what matters. She needs to be clean. She needs to be healthy. She needs to be happy. Dreadlocks don't stop any of that from happening. Instead they help. Her hair will be cleaner without conditioners, her hair will be healthier if it's not being abused every day, and she will be happier because she doesn't need to sit through combings.
I remember being a little girl with a lot of hair. My hair was straight but it would break combs like nobodies business. My mom had to put leave in conditioner in my hair and braid it before bed simply so we wouldn't have to spend an hour brushing it out in the morning. I hated it. I hated bath time because it meant combing my hair. I hated getting ready for school because we had to deal with my hair. I hated my mom because she was the one who combed my hair. The only thing I hated worse than combing my hair was the idea of looking like a boy. I did NOT want short hair.
Are you the one "in charge" of her hair? If so, make your husband do it for a while. See what he says after a week of fighting her hair.
And really, how is choosing to cut her hair short any different from choosing to let it dread? They're both hairstyles that would make life easier for everyone. The only difference I see is that short hair has to be forced whereas her hair will dread on its own for free. And she can keep her long hair. Maybe I'm projecting but most little girls like to have long "princess" hair. Dreads will let her have that without having to brush it all out. (Speaking of princess hair...anyone else think Rapunzel should have saved herself some grief, locked her hair, and made herself a rope ladder? Yeah..that would have been too smart...)
As far as any fears of kids being mean to her...dreads won't change that. Kids are sometimes just mean and if they decide to be assholes they will find anything to make fun of and if they can't find anything they will make it up. I was called fat all through school. Even in elementary school. I looked through old photos recently and you know what? I wasn't fat. Not even slightly. Kids are nuts.
And you know...as far as kids go I'm pretty sure they think dreadlocks are pretty cool. I've never met a kid who got made fun of for having a mohawk, dreads, or funky dyed hair. Kids love that shit.