Hello. Don't know if will be of much help, but here goes:
I was a criminal court lawyer pre-children. It was hopeless, as obviously you have to be in court when the case is on, and can't ask everyone to drop everything as it's nursery pick up time. It was not particularly well paid either; couldn't have paid a nanny. I worked for a small firm, as most court firms are, and they were very good about things like time off for kid stuff, and so on, basically as long as the job was done they were happy. I did, howver, get the feeling when I got married and had children, I was no longer "one of the boys",and didn't fit in as well as I had done when fancy free
I then took a job in the public sector. It was supposedly family friendly, with flexi-time, but was hopeless as I had to use flexi time to go kids' doctor's appointments and so on, but never had time to make it up, because I had to look after children! Anyway, I did not like the lack of autonomy in that job so moved on. It was also very badly paid and the work itself did not compensate for that.
I then began doing what I do now: sitting on tribunals. The work is only a few days a month, and much better paid. However, it is ad hoc so I never know when I will be working, so again would not be cost effective to pay for childcare. DH now looks after kids while I work. He is also a lawyer, and a partner, so has some flexibility.
I loved my criminal law job, but it is not for everyone, and since I stopped doing it people have to work very very hard for ever decresing returns. This is the same with civil court work, and both would be very difficut to combine with family life. Conveyancing has also taken a hit with the demise of the property market. I don't know anything about corporate or big private client work, but my understanding is that the big firms who undertake these demand long hours. I also know that a lot of the firms round these parts have closed when the elder partners have retired.
If I were advising, I would join the chorus telling you not to do it! The course itself is not especially interesting from a purely intellectual perspective, either. What about a related type of study, such as criminology? Thre are probably lots of more intersting courses out there.
Sorry to be dismal. Of course, if you had good family support/plenty other money to pay for childcare, etc, a lot of the above would not apply anyway.
Good luck with this, whatever you decide 