Her husband is providing invaluable DIY on your home. That’s worth a lot of money I’m sure.
They come as a package and stay over, presumably to get the job done, maybe once a month you say. While her DH is busy helping, MIL is playing with your DC…a wonderful thing in my opinion. I’d be making the most of that.
You can sort this problem more easily OP, by accepting their help as graciously as you possibly can and for the rest, change things up a bit to suit your own needs better so that it’s not so irritating for you.
Eg. ‘OK MIL, I’m taking DC out now for an hour or two to give you a rest. Please can you just empty the dish washer/make the lunch sandwiches/prep the dinner veg/just cleanup after the boys for me . - I’ve left everything out ready for you in the kitchen, thanks so much as that would really help and won’t take you long.
Eg. After a meal at the table, you say ‘I just need to make a call, can you please all put your dishes in the dish washer and clear down the table please, thanks that would really help and won’t take you each more than two minutes.
Eg, On the night before the morning they are leaving, you say ‘I’m taking DC with me to the supermarket in the morning so when you get up can you just strip your bed please and put the bed linen and towels in the washer for me and then out on the line so that there’s chance to get them dried and aired ready for your next visit, thanks that would really help me out as I have a busy week coming up.
Etc.