Non-diabetic (possibly what your nurse meant as "normal") levels are as follows:
3.5 - 5.5 before meals/fasting;
less than 8, 2 hours after eating.
"Four is the floor" is a good rule-of-thumb to follow as your BGs begin to stabilise at a lower level. If you take a reading and it's below 4 - or if you feel really "hypo" - crunch up 2 glucose tablets. Test again 15 minutes later; the tabs should have pushed to up into the 4s or even 5s again by then. If not, eat another. They do act fast; even faster is liquid glucose eg Lucozade; many people carry a small bottle with them for emergenciy use.
I always carry glucose tabs (available from chemists and many sweet shops) - I have I pack in my handbag, 1 in the car, and 1 in the house. The first time I tested at 3.5 I did as above, even though I didn't feel at all hypo, and my BGs were safely back up within the 15 minutes.
Once you stabilise and your body becomes accustomed to lower levels, you should lose the hypo feelings. I don't see why, if 3.5 is acceptable for non-diabetics, it shouldn't be acceptable for well-controlled Type 2s as well, provided there are no hypo feelings. For Type 1s it's a different matter - if I had a daughter with Type 1 I'd agree with you completely, carbcountingmum.
Better safe than sorry is a great cliche for all of us!
Viv 8)