Correcting a Mistake with An Estimate

I had given an estimate by email. She had interacted with me ... Before she decided to proceed she had sent me an email. In the email she mentioned that she couldn't find my estimates. So I decided to send her another copy. Most of the time I think I would have just sent them out again without another glance. But for  some reason that I can't explain I decided to have another look at  the estimate. That's when I found some major mistakes that could have cost me hundreds of dollars. After making the corrections I decided to send her a precise detailed account of what had happened and what had been corrected (changed). Below is a copy of the email that I sent to her.
Hi Jane Doe,
I'm very sorry, but I have found some major mistakes in our first estimate to you for the loveseat. I discovered the mistake in the following manner. When you mentioned that you couldn't find our estimates to you, I decided to send them to you again. I decided to look over both estimates before I sent them again. That's when I found some major mistakes in the loveseat estimate. When I had originally filled out the estimate I had correctly listed all the prices in the left-side white areas. However, I had neglected to activate the prices in the columns by placing the appropriate quantities is the columns to the right. (The prices of the supplies and foam and had been left out of all the Options) You can see what I mean by looking at page 2 of the estimate. I have circled the unchanged prices in red in the left side white detail area. What I have corrected is now I have added the quantities (which I've circled in green) in the columns. That activated the corresponding prices for the supplies and also for the foam that are listed in the top description of each colored column. While that only minorly changed the yellow Base column, that has significantly changed the totals at the bottom of the other columns. (The footstool estimate hasn't changed, it was OK.) As before, the prices for working in Client's fabric is shown in green at the bottom of the estimate.
I am very sorry that this mistake happened. I realize that these corrections may make it infeasible for you to proceed, and that is Ok. You can decide to pursue other options if you so decide. Let me know what you'd like to do next. If you have any questions feel free to contact me. Best Wishes, Stephen Winters
I then sent her a text that said:
Hi Jane,
When you mentioned that you couldn't find my estimate I decided to resend it to you (which I have). However, in the process I found some mistakes. You might want to look at them, in your email.
Best Wishes,