Things are still going slow, but steady in the weight gain department for us. She's now made it up to 12 lbs. At the suggestion of a few people I went ahead and purchased a baby scale. I'm glad I did! After several weighted feedings, I've learned she's taking anywhere from 3-6 oz from me when she nurses. That is on par/better than when she takes a bottle.
After several days of research, I'm convinced we have several things working against her weight gain. After yesterday's incident, I'm convinced we are definitely dealing with reflux or GERDs. She actually had projectile vomit, not just spit up this time. After staying with her the rest of the day, it was obvious she was not sick, she was still very alert and playful and cooed and ahhed at everything. The vomit occurred after taking a bottle...but not after nursing... So, I'm wondering if she's sucking in too much air making it worse? Anyway, aside from the reflux, I think we may have a hypermetabolizer. DH and I were both very slender babies, so genetically it would make sense.
I just wanted to say thanks for the support and advice provided earlier. As long as I am changing wet diapers often and she's gaining I'm not going to worry about it.