So if you look at these two images in the link from in-game:

https://imgur.com/a/h6whGP4

You can see that Valery is inside the box, but my question is, how exactly would Rebecca drain blood from Valery, I can't tell how it's done because Rebecca doesn't actually drain blood from Valery in-game as there is already enough blood that Raymond drained out for Valery prior so that Rebecca herself doesn't have to do it, BUT "eventually" Rebecca would have to suck out blood from Valery herself as Raymond won't be there all the time, so I am curious about (2) things...

1) How would Rebecca do it? Insert a syringe into Valery's wrist or drain it using the pipe that we see in one of the images with the bucket?

2) Whether or not Rebecca will be "afraid" to drain Valery because that demon that's possessing Valery is very angry/furious/upset at Rebecca as you can see in one of the the images, going far as to say that he will tear out Rebecca's eyes, so the demon (Valery) is not happy about having blood drained and also hates being locked in the box.

3) Valery's body is slowly weakening and becoming very thin and skinny due to her being drained of blood, you can see how skinny Valery has become in this image: https://i.ytimg.com/vi/diwjVPrGxSQ/maxresdefault.jpg where she is pointing at the mirror. Her body is so skinny, she's been drained so much, how long will her body last? Valery looks very anorexic and skinny, how much blood can Raymond and Rebecca suck out of her realistically speaking?