Red Flags!!

[Shannie]

I charge 700/month

[Lee-Bee]

While I don't think this is acceptable to be getting notably upset about I can understand her confusion. If you check the Calendar she is starting the first week of December, it just happens that December 1st is a Tuesday. So, depending on how you look at it and how her paydays work it could be considered paying for an extra day if she is used to biweekly payments. But again, I find it concerning that she is still notably upset about this after you have explained it to her.

I would also suggest switching to biweekly payments or paying by the number of worked days in a month because charging a flat monthly fee means you work extra days for free many months of the year.

[Artsand crafts]

I charge 700/month

If you charge bi-weekly at $35/day or $175/week multiplied by 52 weeks that is $9,100/year

When you charge $700/month multiplied by 12 months is $8,400

You can run your numbers with the number of unpaid days you have in both options and getting paid bi-weekly will always be more per year. So, if clients are happy because they can understand their payments better and you will be making more per year this would be a much better option imo.