I think counseling would do you wonders and so would al-anon.
The evicting her from YOUR house may be the easy part – that hard part is YOU being able to say what you mean and mean what you say. Being able to speak your needs first then second be able to stand by what you need in your life. Her and her issues out of your home and away from your grandchildren.
Talking to her now, voicing you wanting her out now – is only going to bring you more heartache and fill you with guilt because YOU ARE NOT READY TO DO THIS YET.
Work on trying to detach from her drinking, get yourself some counseling make some new supportive friends in al-anon, keep posting here. THEN you will be stronger and able to stand strong on your needs of her getting out of your home.