Aaron Carter's Fiancée Melanie Martin Spends Thanksgiving with Son Prince, Honors Aaron

Aaron Carter's fiancée Melanie Martin just had her first holiday without him ... and she and her family found a way to honor the late singer.

Carter family sources tell TMZ … Melanie and Prince -- the son she shared with Aaron -- spent Turkey Day with her family. Prince just had his first birthday.

We're told Aaron used to be in charge of cooking the turkey, so this time Melanie and her fam tackled the chore in Aaron's honor ... doing their best to match his skills in the kitchen.

Melanie also kept up another of Aaron's Thanksgiving traditions ... he always liked watching 2 movies on Turkey Day -- "Home Alone" and "Iron Man" -- so Melanie and the brood watched both.

Obviously, the first holiday after the death of a loved one is super tough ... Melanie's sister, Jennifer, brought a four-legged friend to the family get-together ... Aaron's dog Zelda.

TMZ broke the story ... Jennifer and her fiancé Max took in Zelda, the 3-and-a-half-year-old German shepherd, the day after Aaron passed. Melanie was excited to see the pooch.

Melanie made it through a tough Thanksgiving, and she's dreading December, which is filled with holidays and milestones. December was Aaron's birthday month and their anniversary.