My son was VERY private about pooping. He didn't want me there. He didn't fully potty train until he could go poop alone. I bought those flushable wipes, a stool so he could get up on the toilet alone, and would give him his privacy.
Have you talked to her about it? It would help if you could figure out why she isn't going.
With my daughter -- at the beginning of potty training -- she was waiting until her nighttime diaper went on and immediately pooping. We would take the diaper off and empty it into the toilet a few nights, having her flush the toilet. Then we started insisting she sit on the toilet before bed and cheered WILDLY when she went - even the smallest, insignificant little #2. That worked with her.
Have you already tried a reward system? One of my best friends had a heck of a time with her daughter. They tried letting her pick out her own panties. They tried M&Ms -- just a couple -- every time her daughter went #2 and that worked for a while. Eventually they switched to a "Potty Poster" and every time she went #2 she got a sticker to put on the poster. The poster hung on the bathroom door. It was all about figuring out what motivated her daughter.
Good luck, I hope it helps -- you are certainly NOT alone.