Pamper her for a day... it'll be a great day lol
You need to be understanding to the fact she is carrying a human inside her.
Its exhausting, the baby is heavy, we pee every two minutes, hot flashes, nausea, heart burn, acne, weight gain, swollen ankles, hip pain, back pain, boob pain.
I'm sure if you felt like that every single day you would be in a bad mood as Well.
Its very very normal.
My husband gives me massages, makes me a warm bath with candles, buys me pastries on his way home from work and puts me in a much much better mood.
Just simply ask her what you can do to make her feel better.
You'll be glad u did
Well during pregnancy we have alot of mood swings so it's normal