I don't make that good a living from it, but that's mainly because I don't need to - I am lucky that DH has a very good job so my earnings are just pocket money. That said, my friends from college are doing well, and they've only qualified this year. I charge £50 per hour (in London), so if I were to only work 10 hours a week I'd turn over more than £2,000 per month! I guess I'm just lazy.
That said, the work is totally out there - people are becoming more and more active and therefore need more injury management. Also, more people are taking on formidable challenges like marathons or triathlons, and they need massage during their training and as part of their recovery, so there's a really big market out there! I think also having the olympics in the UK people are becoming more excited by sport.
I don't have children but one of my friends does (he's a baby) and she pops him into childcare when she's working. If your children are older and self sufficient I can't see that it'd be a problem for you to work with them in. If they're in school you could look at working in local businesses during the day (this can be very lucrative) - this is a growing sector too. If the phone rings or doorbell goes when I am treating someone I ignore it - they are paying for my attention, not for me to do house stuff at the same time.
I have converted the spare room into a work room but have a sofabed in there rather than normal sofa for the clients to sit on whilst we're discussing treatment and for them to put their clothes on, thus it can house guests when required.
Most of my clients are from word of mouth - I don't advertise. I hand out business cards like they're sweeties and have contacted local sports clubs offering their clients a discount with me. I am toying with doing referral fees for local PTs, combined with a discount for their clients - say charge the client £45 instead of £50 and give the PT a £5 referral fee/credit towards free massage.
I hope that covers your queries - feel free to come back with more questions if you have them.
One thing I did before I started the course with NLSSM was do their introductory weekend. It's a good gauge for how you'll deal with massaging strangers and getting used to bodywork - you might like it in theory but find it icky in practice, or you might (as I did) get bitten by the bug and love it!