I thought it was so cool when my mom came with me to a convention. She's not interested in anime in the least, and she took time out of her weekend (which she wanted to use for gardening) to go to an event that I wouldn't be able to attend without her. She stayed for the masquerade, made friends with another tagalong moms, and had a great time.
For the majority of the time she just stayed in the hotel restaurant or drifted around looking at people and taking pictures of the costumes, but she was right nearby in case I called her. It was great. The only time I felt awkward with her around was when she started getting fussy over my makeup right in the middle of the hotel lobby. Nobody really seemed to care.
It's all good, mate.