Ok, I knew I was tempting fate by saying that I didn't teat dip and hadn't ever had mastitis.
This morning Rowan has got it
Her quarter is a bit hotter than the other one I think, but not hard, and she let me milk her though she wasn't overly happy about it. The milk is very bitty but it isn't discoloured and there's no blood or smell.
I've given her the sheep dose of Tetroxy long acting, intramuscularly, since that's what I had.
I'll ring the vet when they open, but what else can I do for her. Apart from teat dip, which I have done, with a Capriclense solution.