Run - even in primary school when I was relatively fit I came dead last in every race. I get out of breath really easily and I feel like my feet just clomp along.
Draw/paint - my daughter is forever asking me to draw random things for her and they're all barely recognisable. My art teacher in school told me in no uncertain terms not to take art as one of my options. My sister on the other hand was on track to get an A fir art A-level until she dropped out of sixth form.
Sing/play an instrument. I couldn't carry a tune in a bucket! Mind you, my partner is in several choirs yet my daughter insists it has to be me who sings her bedtime songs (Twinkle Twinkle mostly). "No - your can't sing dada. Mama has to do it!"
Have a conversation without feeling awkward/blurting out something ridiculous/getting tongue tied.
Related to the above: not care what people think of me. I'm always worried about people not liking me (based entirely on experience - many people have told me they don't like me), which makes me even more worried about saying the wrong thing and even less likely to just be able to have a normal conversation.
Sew, knit, crochet. My grandma makes my daughter the most amazing jumpers (and used to for my siblings and I as well). I'm in awe and wish I could produce anything even close. She tried to teach me to knit when I was about 7 but I only got as far as a scarf for my teddy bear. I feel like my fingers are too big and awkward for those kinds of activities.
Keep a plant alive. I've even managed to kill a cactus!
I can read, bake and speak fluent German so there's that. I really hope my child inherits her talents from her dad or other members of my family though since I don't have any to pass on!