Weird situation?

I have a question.

So I live with my in laws. There are a lot of people in the house including my s/o’s brother and his girlfriend and their son. I work full time and go to school. My s/o has his degree but he works part time with his friends dad(however he doesn’t have stable income).

My s/o’s brother on the other hand doesn’t work at all and he goes to school but has failed so many classes he is on probation at the school. His girlfriend is half blind meaning she can see but can’t see well. She doesn’t work, goes to school, and gets ssi. The brother gets money to take care of his girlfriend about $200 a month so they get around a grand. The kid was a happy accident everyone loves him as do I. No one else in the house works except the father and sister (sister gets ssi but she actually works hospice care whenever she can).

However my s/o and I have been trying to conceive for a very very long time and his mother knew the day she found my prenatals. She’s warned me to stop and I was confused and hurt but didn’t say anything. BUT just the other day she kept encouraging my s/o’s brother to try for another baby. She made it a competition now. My s/o’s mom keeps saying to his brother and his bros girlfriend to “get pregnant before she does” and i thought it was a joke at first but just the other day his mom and I had lunch and she told me she really wanted them to have a baby. I was confused until my s/o’s sister kept saying she wanted them to have a baby as they made “beautiful “ ones.

I’m here thinking what the...?! My s/o and I work and we’re getting more stable than them so why is she encouraging them more? Also before all of this the girlfriend of the brother had BAD drama with the mom of my s/o (before I moved out) to the point where cps was almost involved and there were threats of the girlfriend needing to be moved out but it all changed?

My s/o’s brother is kind of confused as to why his mom wants another baby and I think his girlfriend too. So I know I’m not going crazy about it.

Soooo is it because she thinks my s/o and I won’t have “beautiful” babies? It’s messed up and I keep dwelling on it so much.

Also anonymous for certain reasons.

Edit: yes as I’ve stated from the beginning everyone lives with each other.