Being a lawyer is never ever easy (apparently!). most of the lawyers i have known in the past have all had nannies to bring up their children. I'm a legal secretary so have never had such a luxury, although i would prefer to bring up my own child, personally!
When DS was young (he's 18 now), i was working every hour that God sent. i was doing my normal 9.30-5.30 job then grabbing every bit of overtime i could get because the money was good (i was a single parent for most of his childhood life). It meant that DS was with my sister alot tho, often over night. As he grew older i found that he too needed me there for guidance but it wasn't until he was 15 and fast approaching GCSEs that i did something about it and gave up work completely for a while. A bit like closing the stable door after the horse had bolted type of thing. he did poorly in his exams and has no real drive in life. I often wonder if i'd have been there for him more than i was whether he'd have been a bit more motivated in life or whether he'd still have turned out the same.
Now, however, i only work 3 days a week and it's great. When i went back to work after Mat leave (DD is 1 now) i was only working 2 days (thurs and fri) and it was more like i was popping into the office for a chat with the girls than working. it was great. now i'm doing 3 days a week i find the extra day a bit intrusive on my life with DD but needs must and i have to do it for the money, at least for another year. I have a fairly standard commute so it's a long day. I leave the house with DD at 7.30am but dont get home and in the door until 7.15pm (DP picks up DD around 4ish).
So anyway, rather than me waffling on and on (sorry!), i would say you just have to work how and when suits you. Dont get caught up in the money side of things and dont let them bully you into doing longer hours or a fee earning job that means your hours could spiral into the late evening.
Not sure if i've helped you there!