I DID IT!! WHOOO!!!!
Okay instead of going mage I went another route(I do not have alex) and went hunter.
This does have some rng in it. For Maexnna have a explosive trap when she has enough spiders to fill up her board, then use UTH. You now have a full board. Now have low mana charge minions or ones with battle cries. Have the health ones to keep yourself up. Go for cards that do not kill his minions and don't have a low health and high attack card or she will be willing to attack it and replace the spider for something stronger. For this deck I decided to use her two greatest strengths and turn them in to weaknesses. You start out with spiders? Now you are stuck with them! You are going to bring my minions back to my hand? Have the right battlecry/charge for any situation! Use it to your advantage.
While these guys at hero mode are strong and have strong cards and abilities, they are still ai/npc(whatever you want to call it) and are not smart as we are. Learn how they play and use this.
Here are the decks I used for Faerlina and Maexxna(I had to delete my lock build):