In most of the games she’s racing against another group, but several times is alongside them or even ahead of them. For example, in the very first game she’s working with someone else who sends her in first to retrieve the treasure, and then steals it from her.
Plus, a good chunk of the time the items are hidden inside priceless ancient artifacts, and Croft has to dig into her British roots to destroy an ancient culture’s legacy so she can get a few bullets or whatever.
I’ve always taken it as they’re tabulating the gifts:
“Wow, today he gave me three french hens! Plus I have the two turtle doves from yesterday and the partridge in a pear tree from Christmas day!”