Selena Walsh you may want to verify they won't be sourcing those funds even though they are a gift. Typically, a gift giver will sign a form stating it's a gift, and then the bank requires them to show a bank statement that reveals the transfer. Any large deposits into that account will be a red flag. But maybe they aren't going to source them at all and you'll be fine. Another way around sourcing funds is a seasoning period. It's usually 60 days. So if the money is in your account, the bank usually only needs to see statements that go back 60 days and the money will appear as though it were always there.
Just to be clear, lenders don't allow Credit to be used as a down payment since that's essentially defeating the purpose. A down payment is skin in the game. If one is required to pay back the skin in the game, it's not skin in the game anymore. They also require gift letters to ensure your not responsible for paying it back since they are not accounting for this debt in your DTI.
Have you looked into low down payment loans? 3% conventional or 3.5% FHA