I would suggest against ANY hollow points in 10mm (for bear) and the Gold Dot is no execption.

100% weight retention does not equate to the same penetration as a non expanding bullet. A hollow point is designed to expand and expose a larger frontal area. That larger exposed area causes it to slow down (shed energy) faster, creating the vauted temporal cavity. The faster it slows down the shallower the penetration. Hollow points actually have less penetration when driven faster, until you reach a point where you exceed the energy necessary to fully expand the bullet, then penetration begins to creep back up as long as the bullet holds together.

I would suggest 200 gr FMJ loaded to reach 1200 fps. That is the original factory load for the 10 mm (though now days it will be hard to find). It should give very good penetration and shouldn't exceed the power level the Glock was built for.

As to whether 10 mm is enough - I can't give anything but theory. I've never had an encounter with a bear, let alone had to shoot one. I would guess that it would be better than a sharp stick or a rock. I would, however, bet that it would be better than a gun she refuses to practice with or refuses to carry.