Second Mom

My sister got divorced about 9 years ago. When that happened, she totally dropped the ball on mothering. The children experienced a lot of pain as a result. I do not have children and was available to fill the void. I became back up Mom. This went on for about 5 years. Now, thankfully everything is returning to the way it was predivorce. She has worked to heal the rift that had developed with her children and help them move on. I’m very happy the story has evolved this way. My main concern is that they are emotionally well adjusted.
What I’m missing is my time with them. My niece in particular. Now when she is bored and wants company she calls her Mom. When she needs to run to Target she calls her Mom etc. She used to be with me a few times a week.
I always wanted children of my own and was unable to do so. I’ve often thought that it turned out as it did so I could be there for them.
I’ve gotten coached about this before. I’m a work in progress 😉

C: I only see my niece a couple of times a month and when I initiate contact.
T: I know she loves me very much but I still miss her
F: Sad
A: Have a crappy moment

Other thoughts:
I was there for the tough teenage years when she was angry and hurt over her Mom’s behavior. Now that she’s an independent happy 22 year old my sister has stepped back in to be there. I KNOW this thought leads to nothing good but it’s there.

I ask myself if this is just part of the 50/50. I don’t know that my thoughts/feeling will change about this to always be positive and happy.
I know that my inability to have children of my own is definitely part of what I’m thinking/experiencing. It’s something I wanted very much. It could be influencing my thoughts/feelings as much as my thoughts about my nieces actions.

Thanks for you input!