Neighbor friends (9 & 5) coming over unannounced. Normal or not?

My daughter (8.5) has a friend (& a younger sister) that live a few streets away. About a 4-5min walk so not superrr close. Their parents send them over here without shooting me a text asking if it’s OK with me.

*EDIT: showing up expecting to play IN the house as it is 100° + most days in Aug until ~7pm. Not at the park/ neighborhood. I don’t mind at alllll asking to play outside

I find this weird and would never ever show up at anyone’s home (or send my daughter) without asking. Even family. I mentioned it to my husband and he responded “well my white friends’ parents allowed me to come over without asking as a kid as as a teen (14-17). We (husband and I) are both from ethnic ‘brown’ backgrounds.

They have came over 2-3x and we’ve had to send them home when we’re busy getting ready to leave the house OR when we are doing family activities. So I told the 9yr old “just have your mom text me so you know for sure if we’re free to play”

They’ve been showing up unannounced now for 3ish months. 1-2x per week most weeks. Some weeks not at all. Some weeks 2-3x. I’ve accepted it for the most part as I know I can just send them away when needed but my aunt was over the other day (she’s a prek teacher) when they showed up and she mentioned how wrong it was and that it’s not safe for me to keep allowing this.

She mentioned 1. What if they head over here and never make it & something happens to them?

  1. What if they don’t make it home from our house

My response was 1. It’s not on me if something happens to them otw here if I don’t even know they are coming.

  1. I ALWAYS tell the parents when they are leaving the house. I walk out the house and watch them for 1-2min until they turn down one street towards their house.

Just want general feedback- do I have a blind spot i’m forgetting/ need to consider for my personal safety?