Need advice

Does your husband understand how you feel? Does he stand up for you?

Find a way to move out.
She will excuse her attitude with being old.

@Jenna not always. He is definitely in the middle. Lately he will say something so I don't bc he needs to come from him. Other days he just takes it in and ignores her bc he doesn't want to deal with it

@Nelly it's our house, not hers lol she should be grateful she's with us and not on the street

@Victoria I keep telling my husband how important boundaries are, especially when it comes to how we parent. This past weekend, she questioned me 3 times on one matter, and I continued to tell her no. Then she went to my husband as if she'd get a different answer from him. I specifically spoke to my husband about that topic beforehand, so we'd be on the same page. But it was more so for my son, not for her.

Does she have her own space and kitchen downstairs? Put a door between the two and lock it. She can only come up when husband is home.

@Jenna yes, she has her own studio downstairs, laundry room, bathroom, kitchen, bedroom etc. We have a door and now "have" to lock it for my son's safety lol my parents babysit 1 to 2 times a week so she'll call my mom and ask to come up and see my son. My mom lets her up because she doesn't feel like she has the right to say no. Although sometimes she will let her know it's not a good time. The catch 22 is that as much as it irritates me, she actually gets to spend time with my son when I'm not home. But when I am home, I miss him so much, I want to spend time with him alone or as a family of 3. If she doesn't come up when my mom is there, I never get the end of when can I spend time with him? Every weekend we run errands together so she does see him but it's not enough.

That is not fair to your mom. She shouldn't have to share her time with MIL. That should be a boundary so your parents can have their time with LO.
Your husband needs to set firm boundaries. Stay in your space unless someone asks you to come visit. She is ridiculous.

@Jenna thank you!! That's what I said. I told my husband how I dont like it, that it's my parents time. He gets it but then asks when is it my MIL'S time. I feel like my parents are helping us and she is just using them to see my son. Prior to my son, she'd never come up or call or say hi to my parents. She doesn't even make an effort or attempt to talk to them, which erks me even more. My family always includes her as she is alone, but she's ungrateful. She is nicer to our neighbors and uses them as well.

Tell husband she can come up when he is home so he can deal with her.

Due to our work/daycare schedules, we are often home at the same time. We have invited her up, but then he has to kick her out.