Miss Maudie is portrayed as a composed, confident woman. She enjoys gardening and is considered a close friend of the Finch family. In chapter 8, Maycomb experiences unusually cold weather, and school is canceled when a thin layer of snow covers the ground. In an attempt to keep her plants warm, Miss Maudie leaves the stove on, and her home catches fire. Atticus proceeds to wake the children up in the middle of the night and instructs them to stay at a safe distance in the Radley yard while he helps the neighbors save Maudie's belongings. The children watch as everyone helps save Maudie's furniture, but her home eventually collapses in flames.

The next morning, Jem and Scout see Maudie outside and speak to her. Despite her unfortunate situation, Miss Maudie remains in good spirits and takes time to have a conversation with the Finch children. When Scout asks if she is upset, Maudie responds by saying,

Grieving, child? Why, I hated that old cow barn. Thought of settin‘ fire to it a hundred times myself, except they’d lock me up.

Miss Maudie then mentions that she plans on building a small home with a magnificent yard, before turning her attention to Scout and her interaction with Boo Radley. Miss Maudie is able to take an interest in Jem and Scout because she is a pleasant optimist. Maudie is not concerned with her unfortunate luck and is able to see the positives in every scenario. She is also a selfless person, more concerned about others than herself. Therefore, it is second nature for Maudie to dismiss her misfortune and focus on the children instead.

In To Kill A Mockingbird, how does Miss Maudie handle her house burning down?

Miss Maudie reacts surprisingly well.  The expected emotion when your house burns down is likely sadness, depression, anger, and/or resignation.  While her house is burning down, the goal is to save as much stuff as possible before it all burns, so there is not much time for reflective thought.  

The next morning though Scout sees Ms. Maudie and is expecting her to be sad.  Instead Ms. Maudie is quite cheerful. She tells Scout that she did not like her house that much anyway.  She also says that she is looking forward to being able to build another house with a larger garden.  

It's possible that she is putting on a "false face" in order to appear strong in front of the kids, but that's not likely.  She admits that her number one concern during the fire was that it didn't spread to other houses.  All in all Ms. Maudie is one positive lady.