We had a similar household growing up - no family close by but a few extended family members who would call , on the "off chance we were home", during a trip to the local holiday destination. Always at a mealtime. Usually with the whole family in tow. Hands hanging, and no warning. (It even happened one day when we came home from school for lunch!). We always went hungry those days, as the visitors had to be fed and entertained (and actually broke toys more than once! And we didn't have a lot of toys given the economic climate in the 80s!).
Nowadays, I work FT as does DH. And as he travels a lot, I have almost all my time away from work taken up with DD. She's 11 now, but still needs a lot of interaction and organizing, and engagement. The constant talk, and answering the same question 20 times in the hopes I will change the answer. Planning ahead for loads of things, when I don't know what we're doing the rest of this week and need a few other things organized first, or to talk to DH about them, but DD NEEDS to be involved and if I completely ignore her, she just decides that it has been decided and will work the way she has planned it in her head, and freaks out if it doesn't (ASD). And she also goes to bed later now, almost when I want to go, so doing housework and getting things organized for the following day get done then and I get no "me time" at all.
I have taken to going to a coffee shop near my office, for a coffee and a couple of sudokus or similar, before work, a few mornings a week. There is 1 person from work who has figured this out, and now tries to muscle in on that time "for a chat" - except I never looked for this and NEED my own space at that time, but she gets offended if I don't welcome her with open arms.