My daughter says I am blackmailing her into having an abortion?!?

My 19 yr old daughter had her first baby a years ago. Very much against my advice but she was determined to have a baby. She lives with her partner who is 10 yrs older. I have my granddaughter 4 days a week so my daughter can work and 1 weekend night so they can have a social life. When she is at home her partner does most of the child care. He walks through the door after a days work and pretty much gets the baby thrust upon him! So now she is 'accidentally' pregnant again. I blame myself a little bit because now I feel maybe I have made motherhood to easy for her. When I told her I could offer no more support she went ballistic and said that I was trying to force her to get rid of the baby. Not so at all, her choices are her own. I just told her I was struggling to cope with the one baby and couldn't handle two. I have two young children too so it's not like I have nothing better to do. I feel so taken advantage of. I've done my best to cushion the blow of being a teen parent and here is where we end up. She's saying that if I withdraw my support she can't have the baby. I say it's up to her to take control. What now?