advice?

So here's the deal I found out a few weeks ago that my mom is pregnant and I don't really know how to handle it. She recently had a baby in like 2016 and it was great but I'm still anxious. She's 40 which is kinda old and I'm worried about the baby a bit but I'm more nervous for how it will change things. We honestly don't have that much money and it's stressful enough. Another issue is that I feel obligated to tell my friends but I'm nervous because my mom isn't married and is only kind of dating this guy and I'm scared my friends will judge me (which now that I'm writing this down makes me realize I probably need better friends). Am I worried too much? Advice anyone?