I'm a sahm, mainly because childcare ate up all my salary, and it wasn't worth the hassle for no financial benefit. To earn more, I needed to go to college and train, but we couldn't afford childcare without an income from me, so it was the most logical option.
Financially, it took some adjusting and learning how to manage money properly. But, all money is family money, and we are ok. We have enough for all our needs, and some wants, so think we are doing well. Because I'm home, I have time for money saving things such as cooking everything from scratch, shopping around, reducing waste etc. I used a lot of convenience items when I was working!
Dh and I do pocket money that's for our own things, it's an equal amount depending on how much is left after bills. Most months it's about €50 each, and it covers things like books, make up, games etc. Kids stuff comes from joint account.
It does take some organising and discipline to keep within your means, but once the essentials are covered it's easier to manage. I will say though, if you have absolutely nothing left after the essentials, being a sahm is grim. Sitting alone at home, can't even get to a playground because it's lashing, or to a cafe to break the monotony, no money for toddler groups or soft play. It would really get you down. There's only so much isolation and at home things you can take. So do allow some days out money in your plans!
Good luck with your decision, it's not easy. No matter what choice a parent makes, it's always wrapped up in guilt. My advice is look for long term gain, on either side!