Splitting capital gains on T3 between 3 people

I have an investment account with my two sisters and received a T3 slip for the capital gains. We each invested equally (ie 33.33% each). How do I claim my portion of the capital gains in the software? I've entered the amounts as they appear on the T3 but there is no place to enter a percentage of ownership. The only related box was to enter "percentage of slip to claim on your spouse's tax return", which does not apply in this situation as my spouse is not part of this account.