Willow has just about finished her season after just two weeks. She stopped standing a couple of days ago and hasn't spotted for over a week, and swelling is almost gone. Normally she goes 3-3.5 weeks. Last night she spotted again, bright and clean like the start. Split season or something else going on?

Seasons rarely 'finish' after 2 weeks.   What's more likely to be going on is she's now over 'standing heat' and for the next week, she'd simply going to have less and less discharge until by around day 21, she'd be out of season.   Could be that, like one of mine who was actually mated on days 12 and 14, she's just having a more coloured discharge which should last for the rest of her season, again gradually decreasing until by around day 21, it will all be over.

Could be a split heat, but that normally means a complete stop for some weeks, or longer (I'm guessing here because I've never experienced this first hand with any of mine) and then coming back into season.

Best advice I can give is to get her booked in for a spay in another couple of months - and of course if this discharge continues and/or becomes copious and offensive, you will need to have your vet check her.  Pyometra is possible - and life-threatening and this is another good reason to get a non show/breedng bitch spayed.

She's booked in to be done in November, assuming nothing is wrong (8 month cycle so she's going roughly 4 months in, at the same time as Ren).

It's just been so different to her last two seasons - spotting to start with, swelling, then standing almost right to the end of them, it's never all gone this quick before!  And she's never started spotting again before either.