While she wasn’t the most buzzed about cameo in the Christmas special, it’s safe to say it wouldn’t have been the same, had she not been involved in the episode.
While she wasn’t wholly herself physically, the spirit and goofiness of Bill played out perfectly, and her presence ended up being the glue that held this whole story together.
Bill ended up being the root of many laughs from the original Doctor, as his mind struggled to cope with a swearing woman who was attracted to the same sex and didn’t enjoy cleaning.
Of course, Bill’s character ultimately became the central character of the plotline ,as it was revealed she was not actually Bill Potts, but a glass figure containing the memories of Bill Potts taken at the time of her death.