Hoping - I think people worry for us because having a child on our own is a lot to take on. Also, the world is still very much fixated on finding a spouse being the natural course of things so some people struggle to adjust to the idea that we can choose to skip the husband and go straight to having a baby.
Anyone who is happily married feels disappointed for us that we haven't found that happiness that they are enjoying and they worry that by becoming a single mum we are giving up on marriage altogether (which I am not, but nor do I see a husband as a 'must have').
Thing is, when I look at all my friends, some of them have lovely partnerships and others do not actually seem to live in the marital bliss we might first assume. In my experience, the dynamic in many couples is that one of the pair is very much in charge and the other has to make all sorts of compromises to keep them happy or there's lots of bickering. One of the reasons I'm single is that I want an equal relationship with a partner; I neither want to be controlled nor be the one who 'wears the trousers'. I haven't found that yet. 3 years ago I was with a man who absolutely doted on me. We'd be married by now if I hadn't ended it, which I did because I knew he was too soft to stand up to me if I was being unreasonable and that the dynamic of the relationship would be him pandering to my every whim - I couldn't stand that!
I suppose what I'm getting at is that although it is the done thing to get married and then have kids, I don't think that is a guarantee of a good life and stable home for everyone. So we shouldn't dwell too much on what we are 'missing' and neither should our support network feel sorry for us for 'missing out'.
We are far better off going into this on our own for the moment, partly because of ticking biological clocks and partly because we may well offer a more stable home to our children on our own than with the 'wrong' partner.
Sorry - I've rambled on for ages!
Hoping - if you want to move back North because you think you'll be happier there, then do it. Your mum is just worried for you; it doesn't sound as though you won't have her support. But I wouldn't move if you're happy where you are and have a good support network in London.
This is something I've deliberated over. If I were to move back North I could buy a nice cottage with the equity from selling my house here, so my financial situation would be far more manageable with no monthly mortgage payments. My parents and sister and three good friends are there so I'd have a good support network there (including a couple of days free childcare a week I imagine). But, my life here is so much fun. It's the first time in my life where I feel like I fit in. I've got wonderful friends and I love the area I live in. There's lots of music stuff going on, where as in the area my parents live there's either one ropey orchestra that wouldn't be enjoyable or a top class pro orchestra I wouldn't be good enough for, so being back there would be the end of my orchestra playing. This is indicative of the fact there are so many more opportunities in everything (sport, arts etc.) in the area I live now, which hopefully my child will benefit from too.
Of course there are areas of northern England where there are loads of opportunities, it just happens that it can't be said of the area I would be moving back to. So although moving North would be the most sensible thing for me to do, if I can possibly make it work financially where I am then I'll fight for that because my life is so enjoyable here at the moment.
I suppose what I'm saying in a very long-winded way Hoping is that if you want to move back up north for you then do it, but don't base that decision on one person (like your mum), or even a handful of people, but on where you think you will be happier.