It is better to do one thing really well than many things not so well.
Figure out the priorities in your life now and focus on getting that done.
(This is coming from someone who has a 3 year old, is a co-founder of an early stage startup, and always has other things to do as well)
I say great, it's great if they're your children. If they're someone else's it's obviously dull as dishwater.
168: Hours in a week
50: Hours of sleep a week (average)
========================
118 hours of work and play
60 hours a week of working
58 hours a week of playing
Of those 60 hours, it's just a matter of priorities that week in terms of what goes where. You can't work full-time on the consultancy, the startup, and be the degree - just not enough hours in the week.
The reason I spell it out like this is that sometimes our mental approach to a problem causes stress for us. If you have it in your head that, "I'm trying to do my consultancy full-time and get my degree quickly", then man - that's just a lot of pressure when you look around and go, "Holy crap - I've hardly worked on my startup at all today! Sorry, honey - I can't play with little {insert_child_name} today because I need to work!" The right frame of mind makes a lot of difference IMO.
Best of luck!
I think three or four "parents" are needed to grow a child in "modern" societies ;-) I use quotes because the price of two working parents [full time] is very high.