Thanks everyone!
Splintergroup - the one he worked with had the right personality (although she does also sniff inappropriately!)
Dave - my husband got a glucose sensor and dropped off on her training. She still does alert sometime (thankfully he doesn't have too many lows).
Ron - you are so right that working dogs like having a job. She was really relentlessly when she sensed he was low -her response was to put her paw on his arm.
Mike - sounds like you have an interesting pair!! Lab would be sad as in real situations, only get rewards when the human is actually low.
Oldrivers - she is a faithful dog and may be the most "in touch" with us. Always knows if someone is sad or upset.
Pottz - dogs are amazing. She would actually beat his technology with alerts before it would show up on his monitor.
GR8HUNTER-dogs have some real gifts!