I made a bj video for my lady friend
That is horrible. Why would you film something like that?
I want to give her something private
Sending a pornographic video of yourself unsolicited could send the wrong message to the woman you are interested in. Particularly if there is another person in the video with you. Talk to your friend to see if this is something she'd like to see before sending it.
She wasn't feeling herself at first but after a few days thanks to my persistence she eventually agreed to watch it.
Even if she agrees to watch it, sending someone a sexual video before them consenting to it is a form of sexual harassment and you shouldn't normalize it. If she's interested with you, she would be the one requesting for things she wants you to do instead of you forcing something to her.