I've already commented and made my point, but I also wanted to agree with the PP that mentioned it is OPs responsibility to protect her child. Even if that threat is from her dog.
I can't force OPs hand.
I had a dog who bit me multiple times, for very different reasons. Once we played fetch, and I tried to get the ball from her mouth and she understandably didn't want to let go. One time I was actively teasing her, because I was young and stupid and didn't think my dog who has shown nothing but love and affection would attack me, and once because someone threw some bread out for the birds, a piece got caught on my jumper and she saw that as a threat of me withholding food, and by this time I was much older and wiser.
It is actually a miracle she didn't attack any one else. I would also have described her as a dog who couldn't hurt a fly. And I would have also justified the bitings as being my fault, but would rehoming her have solved those issues? No of course not. What if someone else played with her and she got too testy, what if some kid didn't understand boundaries? What if some thin-skinned pentioner, who could hardly hold themselves up offered her a piece of their dinner or a biscuit from their pocket and she saw that as them being controlling with food?
I am speaking from experience.
And that dog was a big dog.
My ex-partner had a small dog who had severe aggression issues and it was dismissed just because he was small. Until his grandfather tried to offer him some turkey from his Christmas dinner and he ripped right through the old man's skin, and he spent Christmas in AnE on antibiotics and steroids.
I know there are so many reasons why dogs can bite. Provoked, genetic, illness, past abuse. But why is it fair to pass that on to someone else and how on earth is that fair to the dog? To give it to a family who don't love it as much, for it to go through all of that bonding and suffering and anxiety which might also contribute to further aggression.
At 10 year old it probably is caused by a medical issue. Treating the issue won't necessarily treat the mindset the dog is now in which it thinks it is acceptable to attack.