Oh no! She's flown off the handle again. Why is it that some toddlers seem permanently ready to explode?
As a young child develops she starts to realise she can have an effect on her environment and make certain things happen,' says chartered psychologist Nicola Barber.
But mix this new desire to gain control with a constant feeling of being thwarted, and you have the perfect recipe for toddler rage.
The best way to curb tantrums before they start is to give her a feeling of being in control, even if it's only over something tiny.
Allowing her to feed herself, or choose a toy to take with her when you go to the shops will give her a small, but important, sense of power,' says Nicola.
When she does get cross, keep your body language and voice calm-hard as that may be.
Don't take her rages seriously or personally,' says Nicola. It's all part of her normal development.'
What real mums say...
Harriet is a strong character! But rather than let it frustrate me, I think how it will help her in the future!'
Janie Ford, 34, mum to Harriet, 21 months.
5 Ways girls develop differently to boys
1. At birth, girl babies are already four to six weeks ahead of boys in terms of development.
2. Female skin is significantly thinner than male skin, this means they seem to like to be touched and cuddled more.
3. Girls seem to like to be spoken to more by their parents, which could be why they listen more attentively and keep eye contact more than boys.
4. Girls increase their height and weight more rapidly from birth, and cut their canine teeth ahead of boys.
5. The left hemisphere of the brain, which governs speech, develops more quickly in girls. While the right hemisphere, which is responsible for spatial-visual awareness, develops faster in boys.