As much as Lack of experience can be a factor that can lead to failure in business, it should also not be something that should discourage you not to start the business at all. since you've already mentioned that she has another source of income, it is also possible that she gets to employ people that have the experience in this business and she can learn under them for a while and get experience before she can run it on her own.

Multiple sources of income is always advised, she is trying to increase her source of income, and that is good. Lack of experience should not discourage her.