How can I keep pivot_wider() from dropping factor levels in names?

I would really like pivot_wider to create a column with NAs if the level of a factor exists but never appears in the data when it's used as a names_from argument. For example, the first line gives me a two column tibble, but I'd really like the three column tibble below.

tibble(Person=c("Sarah", "Jackson", "Jackson"), Rank=c(1,1,2), 
       FavoriteAnimal=factor(c("Dog", "Dog", "Cat")))%>%
    group_by(Person)%>%arrange(Rank)%>%slice(1)%>%
    pivot_wider(names_from = FavoriteAnimal, values_from=Rank)

tibble(Person=c("Jackson", "Sarah"), Dog=c(1,1), Cat=c(NA,NA))

How can I get my column of NAs for levels not appearing in my dataset?