3 Year Old a Tyrant About Her Privacy!

I strongly disagree that she shouldn't be allowed to have privacy in her own room. She thinks of her room as her own personal little place where she can do what she wants and her brother is intruding. If not at age 3, then when? I believe children should expect to be treated with respect (and that is what this is, a matter of respecting her right to privacy, unless of course its a safety issue) at any age, by her brother, by her parents and by anyone else.
For practical purposes, explain to her brother that if he wants to play with his sister, it must be in neutral territory. Make the livingroom the designated play zone.

I think she should be allowed her privacy in her room. I think the most important lesson for her is to practice communicating her need for privacy respectfully. Work out a script for her to use with her brother. For example, if after three times she asks nicely for him to leave, then she may ask for your help in securing her privacy.

When her brother needs his privacy in his room, you can help him reinforce that need by modeling appropriate communication. For now, it's not an issue of fairness, not both of them "need" it.

Your daughter is declaring her personal boundaries. Should all of our girls be so lucky as to be able to identify their personal boundaries, clear and confident about expressing them, and having their boundaries respected by others. You're obviously doing a great job raising her!!

I think she has a right to privacy, also.

I have to say, I kind of disagree. I think that she should have a space where she can keep things that are special to her that she doesn't want to share with her brother. Perhaps she'd be more able to share her room with him if you and she went through her room and figured out which things she considers special and put them out of her brother's reach. A 20 month old can be somewhat destructive, and if she feels that her special things are safe, she might be happier having him play in there.

I'm not sure this is really about privacy. When she doesn't want you in the bathroom while she's using the toilet or bathing - that's privacy. Keeping a sib from playing in her room with her toys is about control. If she's not interested in sharing her space and playthings, that could be fine but I think you're right to limit her use of his. Why don't you put the gate up on her brother's door so she can't play in there? If you and your son are peacefully playing in his room that may be attractive to her and she'll be more interested in the party moving to her room. Or not - maybe she'll just play happily by herself, all kids have different personalities. Giving in to tantrums is slippery slope, though, make a decision and stick with it if you can. When our 3 and a half year old has a fit about something he gets removed from the situation. You could take her out of her room into yours until she regains control of herself and then discuss her concerns calmly (all the while the little bro is getting some big sis toy time alone). Perhaps she just wants some special attention from you anyway?
You're the mom, you make the rules. While she's a minor child in your home you're responsible for her and her actions (legally). I wouldn't get too wrapped up in privacy concerns, it may come back to haunt you when she's a teen... the truly scary years!

Removal, time out for the screaming is the best way to go. She will learn.

I am not sure if this will help, but you can try a few things:

when she is in his room playing with his toys, say - ok, in 15 min we are going into your room to all play with your toys. When she has a fit, take away ALL her toys, and give them ALL to her brother. Tell her when she calms down and can share, she can have them back. Let her scream, and ignore it. Easier said than done I know, and the first time she may scream well over an hour.

OR when she plays with his toys, remove her from the room and say she cannot play with ANY of his toys until she learns to share. I would do this with all toys around the house, TV, food, clothes, you name it.

Lastly, I would praise her brother for being such a good sharer over and over and over again in front of her when he does share.

Good luck!