I'd stick with it, but talk to your supervisors about stress and workload. You really should be able to manage a day off on Mother's day and over easter.
Structure your time. And when you;ve blocked out family time, take it, and try to compartmentalise the work so it doesn't creep in. If I were you I'd organise a family breakfast on Easter Day then take the DC out to a local easter egg hunt while your husband has a break. Come home and cook a simple family dinner, giving him a further break, then settle DC in front of a family friendly film (Studio Ghibli or Pixar usually work for 3 and 10 year olds simultaneously) and sit beside them with your laptop doing some very boring basic but essential MA work, like tracing sources or putting citations into the right format.
Do that at least once a fortnight. A whole day off for your DH and a whole day with DC for you. Make a thing of it. And make it easy for yourself. Stay outside the house to avoid making mess. End with a very simple dinner - pasta with ready made sauce or oven baked fish and chips.
Day to day - just ensure your DC get 15 mins of your undivided attention each - a story or chat.
Use TV wisely. No harm in sticking them in front of the TV for a good hour or two a day if what they are watching is worth seeing. Classic kids movies, nature programmes etc.
It's only for a few more months.
And over summer, just make sure you block out your time properly: 6-8 hours sleeping, 6-8 studying max and spend four hours a day with them - giving DHG a break and them your attention, even if you are doing routine stuff together like a supermarket shop or cleaning - just make it fun; let them weigh veg, choose pasta shapes etc, put on music they love while you sort laundry with them etc.
It's an MA not a PHD. You really can do this without ruining your health, your DH's health and your chances of completing it on time.