A daycare mom went off on me: Advice?

I need advice on what I should do about a daycare mom please…i had an arrangement to watch her child for 6 weeks after she gave birth and couldnt work she had a hard birth and didnt have anyone else an di run a home daycare…it wasnt an issue for me because her daughter is very good and i dont mind having her around, so after the 6 weeks she asked me to permantely watch her an di agreed because she does great here…well before the daycare kids get here i go to the coffee shop down the road to grab a coffee, i got stuck in traffic on the way back and was literally 3 mins late…when i got out of the car and noticed a parent was there she legit yelled at me and told me i was being unprofessional, put her kid in the house and then left…but proceeded to text me about how horrible i am for not being on time…i told her i was done watching her child but she said that was ridiculous because i am the unprofessional one and her kid will be back tomorrow and i am going to have to deal with it…i now feel uncomfortable abotu this whole setup and no longer wish to have this kid in my house…how do i get her to understand? what can i do?