Not making enough effort to home school?

I'm starting to feel guilty that I'm not getting through the school work that has been set for my Son. I feel like the reasons I have are really genuine, however maybe I should try harder?

My Son is 3 years old and attends nursery full days Mon- Thurs while schools are shut. He is at home with me on Friday, however I also have a very cling, hard 10 month old baby to look after as well. I am also returning to work after my maternity leave in a weeks time.
On the days he is in nursery, I pick him up, come home and play for a bit, tidy the downstairs of the house, put baby to bed, make dinner then upstairs to give my Son a bath and put him to bed.

I guess I could log on to the video calls on the Friday, however I don't think my Son would sit there for the duration, and I'd be there with a crying baby constantly trying to put him back in front of the camera. We are not fluent in the language of the school, and they don't translate on the video calls.

Basically the only time I feel I have to do the school work is on a weekend, or when the baby is asleep ok the Friday. This isn't a problem but I will always be handing the work in late and it looks like I'm a shit Mum. She also will not sit still and concentrate on the school work. I try and try to get her to do it, but she is not interested.

I'm going to get in touch with the teacher to explain, but I don't want to sound like I'm just making a load of excuses. But I genuinely don't have the time. Is anyone else in the same position? And also do I just sound like I'm making excuses??