Hi, I'd like to help you with your question.
At the age of 14 months, it is hard for a child who cannot communicate well to tell you what is bothering them. They also do not have the capacity to process feelings as well as adults or even older children do. But there are ways you can tell if a young child has been traumatized. Here are some of the symptoms:
Regression- the child reverts back to behavior from when they were younger
Trouble sleeping- not wanting to go to sleep and/or waking up frequently
Misbehaving- breaking rules previously followed, acting out or hitting
Crying or upset easily
Physical symptoms such as frequent stomach aches, headaches, etc.
Changes in appetite
If you notice any changes that last longer than a week, have your granddaughter seen by her doctor. Any abuse can be spotted by a doctor and action can be taken.
But if this problem as not been going on long, most likely your granddaughter is just having nightmares or having some trouble adjusting to the change in her schedule. Most kids like routine and when you change it, it can cause them to react. Reassure her that she is safe and allow her to take anything with her to Dad's that comforts her. Also, have Dad allow her to call home to hear Mom's voice if she needs to. This will reassure her that she is ok.
I hope this has helped you,