I am doing up an invoice for a customer that paid by cheque so I can send it to her email, but see no way to mark it as paid so shes not getting a bill from me

Hello laucek-plumbing-,

It's important you're able to mark the invoice as paid and I'll be happy to help. QuickBooks is a powerful program that enables you to get your work done faster. 

An invoice is marked as Paid once you've received a payment from a customer. You can manually do this and here's how to record invoice payments so your invoice can be marked as Paid:

1. Click on + New.
2. Hit Receive Payment.
3. From the Customer dropdown, select the name of the customer.
4. From the Payment method dropdown, click on the payment method.
5. From the Deposit to dropdown, navigate to the account you put the payment into. You can put the money directly into an account, like your chequing account, or select Undeposited funds if you need to group the payment with others.
6. In the Outstanding Transactions section, select the checkbox for the invoice your recording payment for.
7. Enter the Reference no. and Memo if needed.
8. Once you're done, hit Save and close.

I encourage you to check out this helpful video tutorial that shows you how to receive payments on your invoices. Let me know if this info helps. I'll be here in case you've got other questions. Otherwise, enjoy the rest of your day.