Dog acting weird after dogs death? ?

I am sure it does, since pets can mourn the death of a companion

yes any , humans do the same , dont they ..

Yes, dogs can feel grief.  Yes, dogs can miss the ones who passed away.  Who does this little dog have in her life now?  

She is mourning the loss of the other dog.  Very common when one has several dogs.  They feel the void & miss the other dog who was a constant all her life.  She will adjust just like us after loosing someone we love.  It just takes time.  She is not used to being alone.

Yes the Yorkie is very possibly grieving.  Certainly its world and the order of its life, has been rocked. Not to mention the sudden loss of its companion (that she may have relied on - more than you knew).  So, it has looked to you to help fill the void.  

The usual advice is to keep the home routine the same but to THOROUGHLY clean up all the other dog's scent (wash and/or put away any bedding, any of Rocky toys, mop or steam clean the floors and UP your Yorkies' exercise and play - to help distract her and LIFT her mood.  She may settle and adjust (give it time) or you may decide, getting another dog would be best -for ALL.

The dog has lost its pal and pack leader, so is having to reorder its life to feel safe

The Yorkie relied on Rocky and was very attached to him obviously and probably regarded Rocky as his leader.

Now Rocky has gone and the Yorkie is now relying on your b/f to be its leader and protector and mentor. After all the little dog HAS just lost its best pal and needs now to feel safe and secure.

Imagine how you would feel  if you lost your lifetime partner.

Some dogs find losing a dog friend more traumatic than others and it depends on the closeness of the two dogs. 

Dog do grieve, no question, and she may also be picking up your vibes re this sad loss too which won't help.   And she may well have relied more on her companion than you realised so without him, she's a touch lost.  Try not to baby her or she may believe there is something to worry about - keep to her normal routine and when you are ready, perhaps consider finding her another companion, but that's totally up to you, and whether you think she might accept another new one in there.    I've been in a similar situation with my elderly Whippet (now 12) after we had to let her companion go (younger than her by a year) back in April.  As time has gone on however, and they weren't especially close - he was just there - she seems to have settled down just fine.  It's more me who hates having to leave her alone at home when we go somewhere she can't come with us.

She should come to terms with the situation - as long as she's eating etc.   Sorry for your loss.

she misses the other dog and has become clingy to get the attention she is missing.

 Yes the little yorkie is pining it misses its lifelong friend ya see, So endulge it.