First of all - they need to meet on neutral ground, preferred on outside territory, like in a park or something. You and your mom has to have both dogs on a leash.
Now just walk up to your mom and stand there talking, ignore the dogs completely unless they start fighting. In other words, let them figure it out.
Before you depart, give the dogs a treat, your dog first. She does the same, her dog first. Pet both dogs briefly and then walk away.
Maybe they won't have any interest in each other the first few times, but it will come and you have to ignore them until they both have "tails up" and are friendly towards each other. Then you praise in your usual high pitched voice and reward
You need to meet in this casual, neutral way a few times before you can meet at home.
This is what we have done with Mare who was very aggressive towards other dogs and she now has severel friends
Don't know if it will work for you, but give it a try!