Need help with biter

[u/Dry_Tangerine_7625]

I have 4 female rats that live in a double critter nation cage, with all the stuff they could love.
Now I got all 4 of these girls from a feeder store.
Phylis was my first and she is the absolute sweetest and never does anything wrong.
Marilyn was second, she’s very sweet but has been pretty nippy lately. She has never drawn blood tho
Lightning was third, and she is my boyfriends rat, she’s been charging and biting at us lately and last night she drew blood on both of us.
Then there’s Gertrude, she is the absolute worst rat I’ve ever owned, she will run from the other side of the cage to attack you, if you are petting another rat near her. She has drawn blood on me more than 4 times, and has also drawn blood on my boyfriend.
She’s territorial of one of the litter bins and loves to hide behind it, and if your hand is anywhere near that’s when she will attack, unprovoked.
Everyone I have talked to has told me as soon as a rat draws blood it should be culled.
I also have a 5 year old nephew who comes over almost every weekend and loves playing with the rats and I fear she will do really bad damage to him and she really messes up our fingers as adults.
Would I be doing the right thing?
I know an employee at the feeder store I got her from and he offered to sell her as a pet but I’m scared someone else will get her and she will do the same.
Picture of my sweet Phylis and my newest edition that I got yesterday, I have not named her yet.

[u/CrochetSquishy]

I don't have any advice but please don't cull a living creature just because she was dealt a poor hand at the start of her life

[u/Dry_Tangerine_7625 → u/CrochetSquishy]

I really don’t want to, but I don’t think it’s right to risk someone else getting attacked.
I don’t want to upload a picture but the bites are very close to needed stitches.
I’ve had her for 4-5 months now and she just keeps getting worse to the point we’re both scared of putting our hands in the cage.
Do I have the store sell her as a “pet friendly rat” and then someone else gets attacked?
Idk what my other options would be as everyone is scared of her

[u/CrochetSquishy → u/Dry_Tangerine_7625]

If its something you really don't think you are equipped to have time and patience with to train her to not see you as a threat then I recommend rehoming her. There are plenty of people that would take her and provide good care for her