Wife´s credit card (in the same statement)

[Daniel Trezub]

Hi, there!

I keep separated finances from my wife. We use the same credit card, but she
carries what we call here in Brazil an "additional credit card". I am the
titular holder. All her expenses appear sepparated in my credit card
statement, this way:

My expenses
03/05    Grocery Store A 12.00
03/15    Bookstore        30.00
03/25    Taxi            32.00
03/30    Rent    500.00

Her expenses
03/01    Clothes Store        140.00
03/12    Taxi            13.00
03/30    Soup Store        234.00

Total            961.00

Every month she gives me the money related to her expenses, so I can pay the
credit card bill in full.

The problem is that some common expenses are paid with her card, and others
are paid with my card (taxis, rent for example), and we always split this
expenses.

In this hipotetical example, we´d split my Taxi (32.00) and Rent (500.00)
expanses, as well as her Taxi (13.00) expense, so the 961.00 total would be
split 314,50 for me and 646,50 for her. (hope this makes sense to you all)

Note that I use GC to track my expenses, and she uses any other system she
sees fit, so there is no need to me track her expenses.

What do you guys think is the best way to track MY expenses that are split
with her, in this case?

Thanks for your clever advices :)

=====
Daniel