Your mom's on the right track, honey works pretty well for this. It has properties that help with healing and kills bacteria, so it's not random that she suggested it. The weird look of putting honey in your mouth is the least of your concerns, honestly 😅
What I'd recommend is doing it properly: first things first, take a moment to dry the canker sore with a tissue or something soft. It's important because if it's too wet the honey dissolves right away and loses all its magic. Once it's dry, apply a thin layer (doesn't need to look like frosting) and leave it there for about ten to fifteen minutes. If you can avoid swallowing saliva during that time, even better, though I know it's uncomfortable. Do it three or four times a day and in a couple of days it should start improving quite a bit.
That said, there's one thing nobody mentions: be careful what you eat afterward. If you have something really hot or really acidic (like juice, tomato) right after you take the honey off, it's gonna sting like hell because the area's sensitive. Better to wait a bit or eat something neutral. And if it's still just as bad in a week or gets worse, then yeah it's worth going to the pharmacy, but being honest, with three or four days of properly applied honey it usually clears up.