Signature care medical bill

. My mom doesn’t have insurance and she is visiting USA with visit visa. Due to her age 82 yrs and her preexisting conditions I couldn’t get insurance for her. She had to go er and I took her to signature care which I shouldn’t but I couldn’t think much during that time since she couldn’t breathe and legs swollen from falling. And charged me $25,000. After I negotiated down to $17k. Again I called them next day and said mom is on visit visa and I’m helping her out (in fact I signed as her guardian)because of that they down to $10k but then the lady from round table medical billing department said as long as you are paying $25 monthly, I’m ok. I asked her if they will send to debt collections and she was laughing and said no! I’m so worried because I have one more ER bill yo come with them.

She wasn’t sending me any written approval for reducing to $10k nor pay $25 monthly.

My friend suggested that write her an email saying “as per our agreement today I pay $25 and bill is down to $10k” Not sure it is ok to do

I had nervous breakdown after I saw the bill. I couldn’t tell mom too since she has heart problems. Please. Ty in advance