met dp at 17 & 19, spent a few years doing uni, travelling, working, saving/spending money, moved in rented house together at 22 & 24, and saved as much as possible. Bought our first house together at 25 & 27 dp furthered his career, and I stayed in my long term job as it paid well as was relatively easy (with flexible hours meaning we could get a dog!) so we could continue going on nice holidays and saving money. Decided to try for a baby at 27 & 29 and got pregnant straight away. 2 years later had dd2, and bought bigger house. We're 32 & 34 now with 2 preschool children, and I feel we were in a great position to have children in our late 20s, and very very fortunate for that. If I could change anything I'd probably have had our first a year earlier, and had 2nd a bit sooner too as we would have liked a 3rd baby, but would have wanted them all close together in age. And I'm now keen to get back to working more hours once the dc are in school, and having a 3rd would delay that.
I don't think it's fair for people speculate that "women" who have babies when they're older are always doing so for selfish/silly reasons. Usually the choice is either out of their control, or they've made the conscious decision that being an older parent is the right choice for them for various reasons. Which is entirely reasonable. I think there is alot of pressure on women these days to "have it all" with regards to career, house, partner, children, and sometimes this isnt feasible so I guess then you have to think about your priorites. You CAN start a new career/get married/buy a house in your 40s, having a baby can sometimes be alot harder and occasionally not happen at all for those who wait longer. But that's up to the individual to decide what is right for them.
I also don't think its fair that alot of people think anyone that chooses to start a family before their 30s are irresponsible, don't care who they have children with, aren't bothered about working etc. I hope my experience proves that. I know I was very fortunate to find my dp at a young age and we had the same thoughts regarding buying a house, gaining financial security and prioritising to start a family, while we were still fairly young, but I don't think we're that "unusual"... In my 1st antenatal group, bar one young mum of 19, and one older mum of 36, the other 8 of us were all between 26-30, and all in similar positions with regards to owning houses, havubg long term partners and jobs. And when taking dc to preschool I'd say most of the mum's are a similar age to myself, so probably had their first child in late 20s.