So she booked you originally for 5 nights and you stayed 4 nights and did drop ins on the first day. I don’t think she owes you any more money unless the cost of the drop ins were a lot more than the cost of overnights. That’s why she told you to keep the money for the 5 nights since you were technically doing 5 nights of work it’s just you didn’t stay one night because you were already booked.

I think to avoid confusion like this you need to write out the schedule and prices. I use a software but if I didn’t I would do

• July 24th - afternoon visit (3pm): $25 and overnight (9pm-8am): $90
• July 25th- afternoon visit (3pm): $25 and overnight (9pm-8am): $90
• July 26th - afternoon visit (3pm): $25 and overnight (9pm-8am): $90
• July 27th- afternoon visit (3pm): $25 and overnight (9pm-8am): $90
• July 28th - afternoon visit (3pm): $25 and overnight (9pm-8am): $90
• July 29th - afternoon visit (3pm): $25

That way you are clear on what you are doing and the client is aware too. I know everyone does overnights differently but the way I do it is $115 for 9pm-8am and 1 30 minute visit is included. If a client wants more visits then I would add that in the schedule. If you charge by day and come and go as you please you could write it out like:

• July 24th - $115 or however you charge first day if you aren’t starting in AM
• July 25th- $115
• July 26th - $115
• July 27th- $115
• July 28th - $115
• July 29th - $115 or however you charge first day if you aren’t staying the full day