So they're not going after criminals, just the easy fish? Then why are we having a national debate about all the gang member being sent to El Salvador?

They're going after both - but that's the point. Resources spent rounding up abuelitas and housewives when they dutifully check in at the ICE building are resources that aren't spent building cases against and rounding up the folks that the Administration assured us would actually be the targets of the increased enforcement: genuine bad guys. So rather than having those agents (and lawyers and judges) spending their time on genuine bad guys, they're going after ordinary people who pose no threat. Because they need to get their numbers up.

In the fine print, what does it say happens if you miss your deportation hearing?

You can get deported. I think you're confusing "process" and "outcomes." This isn't a discussion about whether it would ultimately be the result that this woman could be deported - it's about how she was rushed out of the country without being given an opportunity to make a case to a judge that she should be given some amount of time to make arrangements for her infant child.