How many syringes of Juvederm Ultra plus do I need to achieve this look? (photos)

I would inject one syringe into your lips to achieve a result close to the photos.  If needed, another 1/2 to a full syringe could be injected 6-8 weeks later.  You already have beautiful lips, and adding too much would be a mistake.

Thank you for sharing your question and photographs.  I think one syringe will be sufficient to help increase your lower lip volume and pout to better approximate your goal pictures.  Be sure to see a board certified plastic surgeon in consultation as you can anticipate spending between 450-600/syringe.  Hope this helps.