There's a number of good supplements being listed here in the comments, but if she only takes one, I'd advise it to be nattokinase. It is a natural clot dissolver, slightly thins the blood and will slightly lower her blood pressure.

It is not a cure all, but my Russian-educated doctor and I have had many discussions on natto and I know if he were here, he would say it's absolutely mandatory for your friend to heal.

Again, other good supplements being listed here, but natto is a must.