Actually, yes, given the situation, the tide of public opinion firmly and unwaveringly against them, the need for urgency and the ever mounting legal fees and stress related to that, then yes, in all probability, I would.
Put yourself for one minute in OW's shoes, however distasteful it seems to you. Become neutral and think - really think about - what YOU would do in her situation.
They believe the children are okay and being taken care of.
Their actions are desperate and all consuming.
The need for funds - quickly - would override any other feelings, both morally and or ethically, that may have been present before this whole situation arose.
I personally would be doing all and everything in my power to try to extracate my brother and family from this mess.
So, I believe, would you...
I'm certain they are telling themselves that they are doing the right thing by the children by trying to get dad out of jail (and using whatever funds they can get for this purpose) so he can be in a position to provide for them in future. This is perhaps what I would try to convince myself if I was OW, god forbid.