BF weekend is still huge, Monday should be second biggest day of the year, and the next 2 weeks the next busiest weeks of the year. Keep the discount scheme running until yo7 feel you’ve got back what you need. Check the Shopify stuff and your conversion rate it would be unusual to have a big outage and it not to be well known about.
She’s giving 4 months because she is moving and presumably wants to work until ready to go. It’s not reneging on a training course if the business is going to get no use out of it or extremely limited use.