Personally I think some HVs are useless and know very little. That's another post.
Both our hospital paediatrician and paediatric dietician (and my HV, fwiw) have all told me that babies need an absolute minimum of 21 ounces of formula per day until they are one year old, and by about 10 months, the maximum would be about 24 ounces, otherwise they'll not be hungry enough to ear their solids. 10 to 12 ounces is VERY low, are you sure she didn't mean that much per bottle, twice per day, so totalling 20 - 24? 10 to 12 ounces to me would be low in calcium even for a toddler.
I would go up to three bottles, one morning, one mod-day and one before bed, making sure you LO gets at least a pint a day.