Can my ex-wife do a temporary modification of visitation?

My ex-wife bought a clunker and the transmission went out on it yesterday. She lives about 250 miles away with my two kids and we, unfortunately, have to meet halfway for drop off. She wants to make it so that until she is able to pay off the car repairs I would drive there, get a hotel, and pay whatever other expenses incurred. I know I don't have the funds and seems insane that I don't get to temporarily delete my support obligations, but she can ask to stop our agreed divorce parenting plan.

Can she do this without my consent? She has family there that either let her borrow a car or help her rent one, but she has always been the type to find any reason to think I'll do 100% of the driving and incurred costs at her whim.

Now her defense. I was downsized in July and have struggled to pay support. I don't have the funds or a new car to make this journey. So the kids suffer. Plus the holidays are coming up and this year is suppose to be at my home.

Thanks!