can someone use my ip address by them connecting to my network or internet service? ?

[~t~tCaramel86t~t]

I would like to know if someone connects to my Network or is using my internet service will we be sharing the same ip address? my friend just bought a new laptop and it has never had service on it at all she will be using my network to connect to the internet " i know because she lives next door.. l.o.l"... i just want know if she will have my ip address since she's using my connection? if not what ip will she have??? im curious on how that works..