Guys My sister is going to meet her online male friend after 1 and half years of friendship

The guy looks shady and untrustworthy so i am planning to equip my sister with pepper spray and a knife . What else do u recommend ?

U see actually my sister is very naive so i am worried

I am planning to follow her just to be sure coz they are meeting for only 30 minutes and this much time i can bargain from my busy schedule of sleeping and reading manga all day . I also watched " Learn how to fight in 30 minutes " vid from YT just to be safe