The fact that your Amaryllis bloomed every year for your aunt potted as it is, suggests that repotting is not essential if you would rather not try it. However, your aunt was doing something other than what you have done. If she is still available, you may want to get details on her routine for watering, dormancy, etc. If not, perhaps you can recall some details of what she did and try to duplicate them.
The most difficult part may be that the glass container does not have drain holes (I assume) and that makes proper watering difficult. Make sure it gets maximum sunlight when it is growing leaves. Be sure to provide complete dormancy for 8 weeks in the fall.
As others have mentioned, the bulbs are quite tough. You may need a knife to pry it out of its container. If you do so, I suggest that you also try to separate the individual bulbs and put each into their own small pots, although that is not essential.
Repotting may disrupt the flowering cycle this year. However, they will bloom annually if properly cared for. If you use a pot that is too large, then it may take several years for the bulb to fill the pot with roots before blooming. Always keep your Amaryllis as tightly potted as possible.
