My mum wants me to use the silk epil instead of shaving?

ok soo I'm 13 as u guys know .... And like few months ago my mum wanted me to remove the hair under my armpits using the silk epil I actually did it once it kinda hurted me but I did it and the next month I couldnt even put the silk epil on my skin it really hurted me like hell!! So I asked mum to shave with a razor instead she said no it will make ur hair thicker and more!! And I asked her more than once and tried to convince her but she said no soo is there anyway to make using a silk epil less hurting??? Pls gimmie every single detail and you dont have to answer about convincing my mum cuz she would say NO again soo yeah can u tell me how to use it and like wt shall I do so it wont hurt me??? And when to shave?? My mum says better after my period cuz it would be less hurting soo if u have a better time tell me pls :) Thank u :) ps dunno if that's the right category or not :S

This is sort of a half answer since I have no experience with silk epil.

No Scream Cream (http://www.relaxnwax.com/retail) is a topical anesthetic that can be used before hair removal to reduce pain.

Here's an article where a doctor explains that shaved hair does not grow back thicker or darker.
http://www.everydayhealth.com/skin-and-beauty/does-shaving-make-hair-grow-back-thicker.aspx

Also, after shaving "more" hair doesn't grow since it's medically impossible for shaving to increase the number of hair follicles.

She's right about hair removal hurting more near your period. I don't remember the specifics, but it's something about hormones. It's less painful a few weeks before your period, or a few days after.