Sorry about all the deaths in the family. This has to be very hard for all of you. It is NOT an excuse for doing drugs though.
If she is jonesing, she is more involved than you think.
By "in your home" I think what is meant is while she is living at home, not necessarily actually doing them while in your house. It generally is advised to make the drug abuser leave so that he/she is forced to be self-supporting. Any support means more $$ for drugs, or for alcohol if the abuser's drug of choice is alcohol. IF you decide to give her $$, for any reason, gift cards make it harder for her to buy drugs instead of whatever the $$ is for. Even better is to buy the item yourself and give her the item instead of $$ or gift cards.
When you make her leave, change all the locks and keep the house locked whether you are home or not. Also keep the car if she has one you are paying for, or is in your name. If you must, take out the alternator, battery and other parts, and throw them away far from home. Or keep them locked in a safe or other place, so she CAN'T use the car. If her car is in her name but you are paying for it, STOP. It will make her life a bit more difficult. And will make using drugs a bit more difficult.
It really hurts when you ask your child to leave, but it is the only thing left, esp if she isn't willing to do rehab. (if she IS willing, and you are able, then rehab is worth a try - it may save her life IF she is willing to stop using drugs. If you can't finance rehab, check with the local dept of human services, or the doctor's office for places to get help with this.)
I am sorry you are having to cope with this.
Hugs,
Susie