Julie, so sorry to hear about your mare. That and colic are the scary words in my house. Hope she does well.

I have been fiddleling (is that a word?) with foam core board - and glueing mylar to it. Try to get as reflective mirror like mylar as you can get. American Science and Surplus had some. You can take a light stand with a clamp that has a goose neck on it and you can reflect a kicker light where you want without an assistant. I know with moving kids and horses that it can be a challenge. But I love the results.

Both child and horse are lovely!
PS