Yes, but the mum has had to put a roof over their heads herself, since I doubt the maintenance was enough for the son and for housing, whereas the OP and her husband have had a joint income. Plus, the mum might have sacrificed earnings when having the DS, if she took time off work and was then a SAHM until her marriage ended.
ETA: Then there's the fact that the cost of living is horrendous these days and has been rising fast for quite a few years now. Did the husband increase his maintenance in line with inflation? It's hard to afford heating, lighting, housing, food, and other necessities these days for single people.
Then there's the fact that maintenance is to maintain the child, so it's an amount which covers things like food, clothes, activities. It's not an amount which covers the parent's expenses, and not things like the boiler breaking down, fixes for things that go wrong in the house, and all the other expenses of life.
She has been managing all this for a long time on one income, unlike the OP who is much luckier.