Going by what you've said it sounds as though yes you would qualify for UC if you quit your job to become a SAHM. You get a housing element and a child element for the 2 children the deductions will depend on how much your partner earns each assessment period.
Your partner would have to earn £1083 or will be called in to work search.
It would completely depend on partners earnings and your outgoings (whether homeowners or renters (private or social), any savings etc.) but you can use the online entitledto benefit calculator. As long as you enter everything accurately it should give you a good idea. Important thing to factor in is when your partner is paid, if it’s 2 weekly/4weekly/monthly will impact entitlement in the months where there are more paydays than usual, if monthly then it shouldn’t have any impact. https://www.entitledto.co.uk/benefits-calculator/Intro/Home?cid=0221b295-bf7a-4950-a8be-9124e524a813
@Hannah I don’t think I would be called in to work search for a certain amount of time as I would be the main carer for both of our children.
I meant your partner would if they don’t earn the £1083 not you
@Hannah I don’t know if that would be the case as before my partner started working I didn’t earn that much and was never told anything about that
It’s the same for everyone now. Unless your partner receives lcw/lcwra There’s a helpful page on Facebook called universal credit survival
it goes off how much he would earn, but with only 21 hours a week i’m assuming you’d get some sort of universal credit but it all depends on how much he would earn, for mine, they calculate housing, standard allowance, and children. before deductions my maximum possible amount is £881, but then, earnings get deducted, so the first £379 of your earnings is not deductible, but anything over the £379 every £1 you earn over this reduces the amount by 55p, so basically if you go onto your universal credit payments where it says total entitlement before deductions, keep that total in mind, say he will earn £915 every month, £915 - 379 = 536, 536 x 0.55 = 294, you take away 294 from what your total entitlement is. (at least that’s how i work out mine, it should be the exact same for you)