It depends from doe to doe (and again, this is only my personal opinion through experience) but I have seen does change from being mellow and laid-back to being more nervous and/or protective and/or aggressive after they are bred and have their first litter. Sometimes this goes away after the litter has been weaned and left, and other times the change has been permanent.
I don't know why this is; perhaps the process of mothering changes their behavior and their personalities deep down. I had a doe that was very friendly and personable, but with her first litter she became VERY jumpy and nervous. She would lunge whenever anyone came near her cage. She as an amazing Mom though and I thought "Well, this is normal protective Mom behavior, she'll get over it when the babies leave." but she never really did. She never truly went back to the way she was before.
As a breeder, it is *somewhat* of a trade-off because shewas such an amazing Mom and she wasnot like some rabid crazy rabbit to where I would be worried that she would be passing off bad personality traits to her offspring. But knowing what I know now with more experience, if I had intended to just keep her as a pet (and there was a very good chance of that as she was so sweet and calm) I would maybe not have taken the risk and bred her.
Plus there was the superficial downside that when she pulled a bunch of hair for the nest, it grew back a different shade and she just wasn't as pretty anymore.
So I would say that if she is a beloved pet to you, don't risk it.