I need advice... I have two stepsons who are always sick in the winter because their mothers is not…

I need advice... I have two stepsons who are always sick in the winter because their mothers is not the best environment. We recently moved them in the same room with us to make more room for the baby and putting our everything in what we now call a living room ( we live in a very small one bedroom apartment that we converted into two bedrooms). The room is not big at all and I'm now scared that my baby is going to get sick because they are always sick, the house is heated, I'm getting sick and so is her father (he never gets sick). I just realized the problem and I don't really know how to fix it because it gets cold in the living room/ their old room but they cough in their sleep all night and we do our best to sustain it because everytime we get them "better " they come back worse!

Hubby saying she's going to get sick anyways because she's going to be around her brothers but I don't fucking care! It's bothering me now and I think we can prevent it . I mean we are planning on moving by the end of January- February but so much can happen to her until we get the space. I'm so scared. Am I overreacting? They also don't have their flu shots and I don't know if they have their dtap shot updates . Their mother has their insurance cards so it's hard for us to take them to the doctors when needed and she very difficult to deal with period. They are in school but the school don't even have their records because if they did they wouldn't let them be in school with out the shot (they are 3 and 5).

Anyone have any advice on sick siblings at a young age and a newborn?

Yea she has my antibodies but I'm getting sick every weekend because I have to be face to face with them. So I assume she will get sick.

I need help please. I need advice. This is bothering me now. I'm due tomorrow. Induced on the 6th. So talking to my doctor will be hard because I might not see him in time to do anything . Please advice....