How do I limit someone on Facebook without adding them to restricted list?

[Megan]

My boyfriend's sister wants to be my friend on Facebook, but I absolutely do not want her in my business. We are not friends, and she is a huge gossiper. She has gone behind my back before, and I really do not want her snooping through all my personal stuff. However, it will be awkward if I don't add her, and my boyfriend already said he will be really angry if I don't accept her request because it will look bad. Is there a way I can add her but limit the stuff she sees? I don't want to add her to the restricted list because then she can only see hardly anything because it will only show her "public" stuff. I don't want it to be that obvious that I'm limiting what she can and can't see. I really want to limit her from viewing certain statuses I post and pictures. Any ideas? Thanks in advance.

[Butterflied]

They have a custom button you can click right before you post so you can hid posts and links from certain users