Im in exactly the same position, my older cross breed dog is 11 years old and we brought our new yorkie pup home a week ago.
My older dog we have had since she was 3 and she is a spoilt brat lol!
Since we brought our yorkie home my older dog has gone in the huff and at first she wouldnt even stay in the same room as the pup.
My older dog is a bit scared of her too as when my pup wanders over to her she runs away... but shes coming round a bit, she now sits in the same room but is still very quiet and jelous.
I think they will just need time to get used to the situation and hopefully they will come round to the idea
Good luck and let me know how your babies get on x