I get why you feel this way. I see a lot of people saying she did it herself but that doesnt help your conscience when you made the call, so I'll break it down for you more: you may have made the call but the real problem is she created a perfect storm of conditions for things to go wrong. Wanting a break means she should have had at least 2 or 3 emergency backups in case something happened to the kid. Lines of communication cannot be eliminated without planning ahead of time. Her response to you tells you that she deliberately endangered the kid>prepping for time on her own. She had no emergency contacts for you (!), no doctor list to call, no resources for you.

You feel bad because you made the call but the alternative is... what, exactly? You google how to care for a baby? You could potentially create a much worse scenario. Diaper rash, choking, injury from improper handling, issues with lack of food, etc you literally chose the option that ensured safety for the kid. Mom's situation sucks because it led to her losing her job and the drugs. However. She made it worse by not having contingency plans. She made it worse by removing your ability to reach her. And nobody engages in those choices re: drugs without considering the risk. She chose the risk of that over being safe. She can attempt to get her records expunged, enter programs for single moms, and keep trying to create better conditions even with that felony conviction. You cant assume responsibility for the actions of others because you had a hand in their fallout or you'll drive yourself crazy with guilt. It's okay to feel bad but ultimately if she hadnt had drugs or hadnt been so far or hadnt turned off her phone, or even left you with a list of emergency contacts, this wouldnt be so bad.