Answer:
$0
Explanation:
Data provided in the question
Loaned amount several years ago = $6,000
Long term capital gain = $4,000
Based on the above information
Lisa is not in the position to subtract the loss from the loan i.e. uncollectible as according to the Internal revenue service (IRS) it is mentioned that if the loan is given to a brother the same is treated as a gift
So, the amount would be $0