My DS who is 5 in dec...does that sometimes....he says its a bad dream or because he misses him while he was sleeping.

so i ask him what his dream was about and then tell him, that its ok now, it wasnt real and it was just his head being silly with him....and it seems to work.

if its coz he missed me....i say i missed him aswel and im happy to see him and we have cuddles.

i guess try and ask her what is upsetting her so much. and find away to make her feel better