Well Eleanor some of us do, or with very little childcare, I took ds1 with me when tiny and once he was bigger I had the bare minimum ie only tutorials and lectures I had to attend where he was in childcare. Cost mainly as even though it was subsidized it was still expensive.
So I studied whilst he played, read whilst bfeeding and when he slept he hardly slept until he was three yes old and yes it was hard work, and I was knackered at times, but I enjoyed it and have fabulous memories of his baby and toddler years on campus, he took his first steps in the uni bar (the back bar non smoking). I made one of my very best friends during that time and we both managed to graduate babies in tow.
The system needs to be flexible, many units already (as evidenced by this thread and experiences of others) let little babies attend some lectures and seminars. Its never a long term issue, as they get bigger they can go to nursery, are easier to leave etc.
But for some parents the flexibility of being able to take a little one until old enough for nursery or in event of childcare letting you down is vital in them succeeding and completing their degree.
Is it ideal? Maybe not but life is far from ideal, we all muddle through best we can.
But you can complete studies with young children, even without childcare, hell thousands do through the OU. I had no more than four hours a week and I bust a gut keeping up with reading, getting copies of notes etc for lectures I missed. Not ideal but entirely possible.
This student wants the opportunity to try, if she tries and it doesn't work then work on option b, but letting her have a go for a few short weeks, op says til easter? May help and make her life easier.
I echo what Bertie said a few pages ago re social side etc as well.