Hi Amelia,
Welcome.
It is a little unclear if it is your or your mother-in-law who wishes to meet Jackie. I think you might have more success if it is your MIL rather than you.
You can write to Jackie here and thank him in a letter:
The JC Group
No. 70 Pak To Avenue
Clear Water Bay Road
Clear Water Bay
Kowloon
Hong Kong
Good luck. Remember every fan wishes to meet Jackie, but this is very seldom arranged unless there are very special circumstances.