You sound like you have been staying (outwardly) calm and professional towards her, which is definitely the right way to go if you want to increase your chances of getting paid. In most cases like this the person does pay in the end, they are usually just absolutely rubbish at organising their own affairs and have loads of other stuff going on in their lives. Of course, there is the one in a thousand who is not going to pay and court is required.
After about 30 days of non-payment I usually explain that I am a small business, just myself and that late payments have a huge impact as I am unable to pay my own bills on time. Play on the heart strings a little, professionally.
Don't get put off being self employed
@Sookme . It's great! I have had perhaps only 3 customers over my 8 year self employed period that have stalled paying for longer than 30 days. Even they have paid in the end. You have just been unlucky that you have had this right at the beginning.
Definitely have all quotes written down, plus send all changes to a quote by email so there is a paper trail.
Let us know the outcome in an hour
She sounds pretty chaotic so I bet she doesn't pay by 11am, but I bet you get paid later in the day of over the next few days. We should start a poll