Several years ago I had to do something similar with my very first Yorkie baby and it tore me up so bad
When my ex and I split up I left my baby while I moved to a new apt. and started a new job. I visited her every week but as time went on I could see that she and my ex had established a special bond and were so happy together that I gave in and agreed to leave her there permanently. I now have 3 Yorkie babies that I love dearly but I will never forget my first baby as she has a special corner of my heart. Loving a baby enough to put their happiness first is the most selfless thing we can do but it sure isn't easy!