How to Pray for the Dead?

I saw that it is not recommended to enter shrines if one is mourning.
My 7-month-old niece unexpectedly passed recently, and I would like to pray for her/memorialise her while in Japan.
What is the correct/polite way to go about this?
Thanks for your time.

I am sorry for your loss. I unfortunately wonder the same thing as I would like to memorialise someone very dear to me. Does somebody have the answer?

I'm sorry for your losses.

The short answer is: If 50 days has passed after whoever it is that passed away, you don't have to worry about it. You can enter shrines and pray just like anyone else does. For the OP it's just 10 days, which has passed already.

http://yakudatta.com/archives/284.html
http://www5.ocn.ne.jp/~nanko/hukumokikan.htm