Very much so, a lot of the illustrators that I speak to are supporting families and have all the usual outgoings just like someone who is on a regular salary. It's definitely not an easy aspect to cope with with the lack of security as a freelancer but it is definitely something that gets easier the longer you do it. With all the different sectors of illustration available today theres even the potential to bring in a six figure income (especially working in advertising), I have also read some children's book illustrators are millionaires! Granted they are the cream of the crop, have an outstanding reputations and have been established for a while but the point is that the potential is there.

I think the key to it is to be realistic, work out your daily outgoings and the income needed to accommodate them, then work as hard as you can to double and even triple it.