Prayers for Erin's family, and friends as they might be hearing information for the first time today.
As for rescues, I've been involved with many over the years, and what I've found is that some start out with the love the animal, and at some point, greed took over. While I realize it takes fundraising to keep any rescue alive, sadly that's all some focus on. Not just horse rescues either. Even the ASPCA spends more money on fundraising, and paying their own salaries than on actual saving of animals. And yes, whoever is in charge of a rescue can receive a salary from the rescue! Some even purchase land, and then rent it to the rescue so they are receiving rent money each month for the rescue they run on land they own!!
Some rescues have a return policy for any animal adopted from them. So that at any time in the life of the pet, your circumstances change and you can't take care of the animal, it can be returned and rehomed. Some own the animal for it's lifetime, and can't exchange ownership with someone else, can't sell it, give it away, or even have it euthanized without the rescues OK. Others, once you adopt the animal, it's yours to do as you please, even rehoming, however most you sign forms you won't ever breed the animal.
As with just about anything in life, there's good and bad rescues out there. Research as much as you can before donating funds, or adopting without knowing the full contract. Also realize that most of the animals are donated to these rescues, usually meaning they got them for free, and then charge whatever amount they want for adoption, in some cases the adoption fee is higher than getting the animal from an individual. Some horse rescues require you make a monetary donation to their rescue before they accept the horse into their program. They then charge an adoption fee when the horse finds a new owner. I've only seen that once in dog rescue, and the amount was $1500 for them to take the dog!!!
The legit rescues that are out there have no problems with you asking questions, wanting to see their funding activity, how active they are in the community, etc. \\JMO