How much have I spent in real money on Roblox

Roblox seem to want to hide away how much I've spent (paid) on the game, or, I do not understand how to traverse the maze of menus.

I am trying to learn how much I've spent on both of my daughters.

I log into Roblox in my browser, and I click on the Robux symbol. A drop list opens, and I choose the first option (which shows how many Robux remain). This has taken me into My Transactions.

If I review summary, current purchases or purchases, it shows the total number of Robux (which is the name of the currency in the game) I have bought. I do not see how much real money I have spent (in USD$ or GBP£).

I can't simply use email receipts because there is no way to know which of my daughters each receipt is for.

Is it possible to get this?

According to a Robux to USD website converter I managed to find here, you have spent roughly $56.25 of USD on Roblox, due to a constant rate of one Robux being worth $0.0125.