There ain't nothing wrong with second hand. Bonus if you can get things new, but i think she was naive to think that she could afford, brand new "decent" clothes, nappies, toiletries etc, all on that £10 a week.
I wouldn't want to call her immature or a bad mum or anything coz we didnt see her post birth, she may have grown up... but she really did have her head in the clouds with the whole thing.
Although i thought it was mean of her mum to wish her a horrific labor and birth... she could have said something a bit different...
She just needs to wake up, and i'm sure she has by now... but she didnt give us teen mothers a great name or reputation.