In our family, we have just always helped each other out with a huge variety of things and never thought twice about it! Whether it was shopping for a gift, starting dinner, calling Grandma to check in on her, depositing a paycheck (something my boys have done for me multiple times) running something to the post office, running a forgotten item to school, the list goes on and on. We have always just helped each other out. My 26 year old son lives on his own and I still do things for him and he does things for me! (Last Fall, I had to have an unexpected medical procedure done. It was minor and done in the office, but I couldn't drive afterwards. My husband had just had his knee replacement done and couldn't drive. I called my 26 year old and asked him, if he could take a few hours off from work and drive me and bring me home. Because, we have always made it a habit of helping each other out, I didn't mind asking and he didn't think twice about adjusting his schedule to do it.)
In fact one of the things that I have done for him, is giving him gifts for his work Yankee Swap for the last three years!! They have their office party at the end of January after the Holiday rush. I have had leftover gifts that I ended up not gifting and have passed them on to him, which he has gratefully accepted.
Every family is different, but I am forever thankful that in our family we just happily help each other out. Something as minor as grabbing a $10 gift for a 16 year old's party wouldn't even be a blip on my radar!!