I wouldn't worry that you've lost here. I think you hit the nail on the head when you mentioned she might be tight financially now that she built the horse arena. She probably just needs to build up her funds a little bit. It doesn't help you out I know, but you'll probably still have her come spring time. Maybe you can explain that the drought set things into slow motion some this year leaving her with the false impression that mowing season must be ending earlier this year, but now that rain and ideal growing conditions weather wise are here, the grass will need cutting more than she thinks it will. You can also explain that any leaves that get left on the turf will be four times as hard to get up and clean off come spring time, which will result in more cost then, than now.