You've done "her" ironing, have you? And you've "helped out"? Oh, okay. Be honest, did you do it on your own initiative, or did she have to remind you that things needed doing? Look around you- are there piles of laundry, dishes that need cleaning, toys all over the floor that you are ignoring?
So what housework would you do if you were on your own and working in London 5 days a week? That's right, you'd keep your house clean on your own. You'd look after your own ironing and cooking.
Because as a fully-grown adult living in a house, that is your responsibility.
She is your partner, not your mum and not your housekeeper. She sounds overwhelmed.
Looking after children is a mentally-draining and exhausting job. Sometimes it can be downright depressing and not particularly mentally stimulating.
You two need to have a chat. Send the kids to grandparents so you can be on your own. Talk about how she's feeling about the housework and childcare and make a big list of all the things that need to get done in a week. Ask her whether she needs to get herself a job outside of the home to feel more fulfilled and less stuck in menial work.
If you can afford it, employ a cleaner. Get a dishwasher. Pay for afterschool childcare.
Agree what you will do and do it automatically without asking and do it thoroughly. Don't give things a quick wipe down with a dirty rag and think that'll do it. Maybe ask your other half how she does it, so you know how to do it properly. See things that need to get done and do them- if you see some clean laundry, fold it and out it away. If you see dirty cups lying around take them to the sink to get washed. If you see dirty things in the sink, clean them.