Leech Jimmy and Black Alice?

can he temporarily block access to her abilities like others ?

Jimmy is reputed to be able to disable magic
but I'm not sure how it work

No.

Leech's abilities only work on characters with the X-gene--which Alice obviously does not have. I know there are a few exceptions to that rule, but they're so few and far between that they may as well be considered outliers, imo. /shrug

Anyway, his abilities aren't going to affect Alice.