This type of tenant was my bread and butter and I never had problems with them. I did interview them very thoroughly though.
Im not entirely clear what you mean by the payments, but you need to be careful with them in case some of the money could be interpreted as an illegal deposit.
Third party credit checks will be of little value with a new arrival. I would do it myself, looking at bank statements, credit card statements, savings, employment contract, references etc. This needs to be done BEFORE any contract is signed. Dont forget to request her Right to Rent share code too.
I would echo Mark’s suggestion about training. Mistakes in this business can cost you 10 years profits.