M.B.
My 5 mo old also feeds twice--occasionally 3 times-- in the night. I have identified the times she's really hungry; if she wakes outside these, we put her back to sleep without feeding.
We figured out when she was really hungry because at some times, if we don't feed her, she'll go back to sleep but wake every sleep cycle until I nurse her (after that, she'll sleep a few hours straight). She's waking because she's hungry, and the waking is solved by feeding. However, if she wakes at 9:30, say, she can and does go back to sleep for a few hours before she needs to eat.
You'll hear a lot of moms talking about their babies sleeping through the night at this age. Don't let that discourage you. It's totally normal for a baby to still eat in the night up 'til 1 year old.
You might try pushing back her first nighttime feeding (babies usually sleep the longest in their first stretch) ... say, try just putting her back to sleep without feeding until 1 am (if she sleeps 8-1, that's a 5-hour stretch with is technically considered "sleeping through the night"). See how she does with that. I'm not at all a fan of letting a baby go hungry, so if she does seem really hungry, feed her! Every baby eventually gives up their nighttime feeds when they're ready. :)