If you're willing to make a substitution to your team for this battle then I would recommend a couple things. A strong Ice type would be able to kill the gliscor pretty easily. Piloswine learns ice shard by level up and Mamoswine would do really well against her team. Brongzong with Levitate also completely shuts gliscor down. Oh and if you got Larvesta from the mystery egg in Jasper Ward you can completely sweep her team since Quiver dance's power is double