Just for a different perspective - I was that child. And it was bloody hard work!
My mum stopped work the second she found out she was pregnant with me and didn't work another day in her life, I'm 27 now.
All through my teen years, I had to stay in to 'keep her company' rather than going to see my friends, had to ask/arrange weeks in advance to go out and even then got the guilt trip "so I'll just sit here on my own then while you gallivant off again..." etc
I have 2 DC now and while I obviously adore them, I am careful not to revolve my whole life around them, still work PT and see friends occasionally etc (much to my mothers dismay that 'I'm not a proper mother if I'm not there for them 24/7')
It also affected the relationship with my father, my mother was the perfect parent who always knew best so he backed off and we're not close now, barely speak so DCs spend lots of time just on their own with DP
It also broke my mother when I went off to uni and she got very serious depression, which she reminded me of regularly, again a big thing to deal with at 18 so DP and I are already (even though DCs are little) thinking of things we'd like to do when they move out