I have taken this challenge (not from your niece's post) and I know that being thankful has helped me to maintain a happy, confident and generous disposition. Being thankful makes me aware that I am surrounded by blessings. I feel I belong to the group described in Jeremiah 17:8(NLT). I repeat this several times a day:
"They are like trees planted along a riverbank,
with roots that reach deep into the water.
Such trees are not bothered by the heat
or worried by long months of drought.
Their leaves stay green,
and they never stop producing fruit."