Instead of taking the hinges off the door in the episode where Becky gives Roseanne the silent treatment.

Oh yeah, plus the hinges were on the wrong side of the door. They were on the inside. She wouldn't have been able to take the door off without going in first.

I thought the bathroom only had one door, so what do you mean?

You are right there was only one bathroom door in the girls room. Dan and Roseanne were the ones with two bathroom doors. and it doesn't make since how she would have been able to take the hinges off on the wrong side of the door. mistakes, mistakes, mistakes

The bathroom also had an entrance from DJ's room, which was made clear in only a couple of episodes. (One that I can think of right off the top of my head was one of the girls saying that he (DJ) must have gotten into their room through the bathroom). So, Roseanne could have just went into DJ's room, went into the bathroom, through the bathroom, and then into the girls' room on the other side.

I always thought DJ had his own bathroom and the girls bathroom only had one entrance -from their bedroom. It makes sense now though during the episode where DJ locked himself in the bathroom with a woman's magazine because Becky complained to Roseanne how he was always in the bathroom.

There was an entrance to the bathroom from DJs' room. Remember when Darlene came in and saw Jackie with the bruises???

I think the reason she couldn't go in there from DJs room is simple.. Being a bathroom, I am sure it had locks from the inside on both doors. All Darlene and Becky had to do was lock the door from the inside. ;)