Please don't use the wormer on her, it would be an overdose and could make her ill, if she's 2kg in weight , it's about three times the dose she needs.
Your vet can sell you the right dose drontal or milbemax tablet for her age/weight.
If the vet says she's old enough for Drontal [think 6 mnths is usual] then the dose for a 2kg kitten would be one HALF of an ordinary cat drontal.
OR you could buy a milbemax tablet for her instead.
The same with the flea treatment, it is basically a toxin, you could make her ill by using too much, she needs the correct size pipette for her weight.

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