Annoyed by my daughters littles friends?!! (Long)

Hi everyone! I'm a mom of two -a 6 year old girl and a 8 month old baby boy. I work part time and the rest of the time I'm at home with both my kids. Mind you, I'm at home literally doing what any mom would do. Cook, clean, do laundry you can guess the rest. All while my husband works the night shift and does a lot of over time. I'm also helping and visiting my mother since she is struggling with breast cancer.

I'm just always tired! I feel like I have a lot on my plate. And when I get home all I want to do is rest what I can. And every time I get home literally a group of kids comes knocking at my door wanting to play with my daughter. Especially this little girl who is lives 2 apartments down from us. I barely moved here and these moms I swear they just don't care about their kids -This one girl is always at my house for several hours. I don't know this girls mom but her mother never tries to come looking for her. Only once!!! And she doesn't try talking back when I talk to her or make conversation outside. We are neighbors for crying out loud. Also, I hate to be mean but every time I send her home she leaves crying. Or she cries if I don't let my daughter go outside. I don't know these people so I'm very over protective and let her go outside for at least 2 hours (with me going outside every 5 min to check on her) But my main focus is that I never get any naps and I used to get naps before I moved here! Kids are always are just always at my house going through my fridge or in and out my bathroom.

What should I do??? I don't want to seem like that grumpy new neighbor.