S.G.
Yes it is very possible at her age to be going through this and completely normal. All of her behaviors are normal and to be expected too. She will get better over time. If and when he has a chance to call home, let her talk to him. Let her carry his pictures around if it makes her feel better. What ever she needs to do to cope with him being gone. Just remember, she can't express herself like we can when our hubbys are deployed. Here is a website I thought you might like. They make dolls out of pictures. http://www.daddydolls.com/index.php
You might also want to show her a calendar and mark off the days till daddy comes home or make a paper chain for all the days he will be gone and then cut off a link every day. She won't understand the concept of time but it might give her something to look forward to when the big red heart come on the calendar or the last link is left hanging!
Just hang in there and hopefully she will relax soon.
S.