So I am worried..

Ashy • I have two amazing boys, born 05-30-2015 and 04-07-2017 and we are going to have another baby in December 2018😍😋
I need some help my sister in law has been pregnant for awhile... Not sure how long honestly and she doesn't remember her last period month or day... The baby kicks she is about 5'3 and was 145 before and is about 185 now...  She won't go to the doctor (drug use) so please don't comment on that I have tried supporting her I've tried making her and nothing works according to the weight she's gained how far along do you think she is?