Before launching into a friends with benefits arrangement with anyone, it's important to have an open and honest conversation about expectations and what you each want. I assume this is a friendship you each value. Do you both value it over the opportunity for bicurious sex? Here's why I ask.
Anytime sex is involved, particularly sex with the same person over an extended period, emotions WILL play a role even if you don't anticipate becoming romantically attached. You might think you can maintain your current friendship "as is," but your relationship WILL change. You need to have a long talk before becoming sexual with one another. I'd say the same thing to a male/female friendship couple. Having sex changes any relationship in ways that cannot be undone.
Here are a few issues to think over and discuss. You probably won't have the answers for everything, but the questions should at least be talked about:
1) How long will your arrangement last?
2) What are the "rules" in your relationship for dating and having sex with other people?
3) What happens if one of you enjoys the arrangement more than the other or falls in love and the other doesn't? Will the friendship survive?
4) How will you know when the "benefits" are over?
5) What's included in the "benefits" and what acts are off-limits?
6) How will you introduce one another publicly?
7) Will you express affection publicly?
8) Will you hide your arrangement from other people (family, other friends, dating partners, strangers)?
9) Since you are both bicurious, will you be exploring more about LGBTQ issues and culture to help you with sexual identity?
10) How will you handle jealousy?
You had also expressed concern that your friend may just be going along with you and telling you what you want to hear. Make sure she understands that this is not something to just go along with. She has an active choice in this, and if she's not 100% onboard, then you shouldn't make this big change to your relationship. Pay attention to her nonverbal language as well as what she says.