Should she get another Guinea Pig?

So I have a situation that I would like to see the results of from Glow community!

In my household, there is/was 3 dogs (two of them are my parents’ and one is mine) and a guinea pig that belonged to my little sister. To keep them separated, there was a baby gate on the stair and the guinea pig was in my two younger sister’s room. Well, a week ago, my mom took the gate down, saying she thought the dogs wouldn’t bother the guinea pig anymore. I had even told my mom I thought it was a bad idea bc the dogs were constantly upstairs after, but she said it was too late and she threw it away.

Earlier today, my boyfriend came back from the ER (he had really bad back pain) and had taken my dog to lay down. I was trying to help him get her to lay down when I heard a noise that just didn’t sound right, so I jumped up and ran out to find the oldest dog w the guinea pig in his mouth. I grabbed the guinea pig but as I did, I realized he was no longer breathing 😭 They had pushed down the cage and the top piece fell off so they grabbed him.

I know my sister is going to be devastated bc she loved him. I offered to buy another But my mom said she doesn’t want another guinea pig in the house. I know it is a “her house, her rules” situation so I’m not pushing it, but myself and my older brother think she should be able to have it replaced if she wanted it to be bc it’s not her fault. So I’m interested to see what everyone else thinks