<human>: Condense the text into a few key points

My sister just dropped a bombshell on me: She just found out that her husband of 7 years has been cheating on her for a year and a half. Sickeningly, this was happening even while she was pregnant with their second child (who was born last week).

She's about to become a single mother of a 2 year old and a newborn, with no income, and little financial ground to stand on.

I've gotta think that there are a lot of other redditors who have had friends (or themselves) go through something like this.  All I want to know is what can I do to help?  

I'm not asking for gifts/handouts/anything other than just good advice. I imagine the road in front of her is going to be long and hard and I want to know from people who have traveled it: what is the best thing **I** can do to help her?
<bot>: Sister is about to become a single mom with a 2 year old and a newborn.  What is the best thing I can do for her?