What To Do

Eli is on My Dog Training Center's list for the upcoming Introduction to Agility class. Not only do I think Eli would have a lot of fun doing agility and would be great at it, agility is beneficial for reinforcing commands between a service dog and handler, as well. I have really been looking forward to starting this training together.
Eli is a little over nine months of age now. At this point he is beginning to grow into his adult personality. He continues to display very good manners in public and certainly knows he has a job to do. While he does not want to be bothered, he accepts a friendly stranger when I hand him over to the person. It still amazes me how many people just do not know service dog etiquette. People reach for him, talk to him, make noises to try to get his attention...these things make for a stressful outing for both me and Eli.
Eli growing into adulthood has been producing some changes with our family dog, Mei-li. In general, Mei-li does not care for other animals. On ocassion the two get along and play together. Lately, however, there has been more battling between them than friendly play. It breaks my heart to think that Mei-li and Eli seem to be increasingly unable to live peacefully together. Of course, Mei-li was here first. Recently, too, she has been wanting to go everywhere I go. Because of that it seems Eli has been marking me, or at least marking where I spend time. He has taken up marking my side of the bed and even my recliner. There are times when Eli really seems uneasy. He gets nervous and even my husband says Eli seems to be feeling insecure about something. It is very painful to me to think that neither Eli or Mei-li are living the happiest lives they can due to not being able to live in harmony with one another.
I do not know where to go from here. This is an extremely sad situation. I cannot imagine what it would be like for Eli to retire as a service dog and live with someone else. I have a feeling it would devastate him. I know he would be looking for me. Not only that, but all he knows is being with me constantly. If he had to spend time alone it would probably crush the little guy's soul. What do I do about Mei-li, though? As I type with Eli laying on my shoulder, Mei-li is laying on my pillows in the bed. This is something recent she has been doing. It seems as though they are fighting over me. Yet, Mei-li has always been more of a "daddy's girl," so I do not understand it. I hate to think that she is going to be miserable every day of her life now. The fighting between them is just getting worse. If they are jealous of each other I do not know how to fix that.
I suppose there is no easy solution. I just do not know what to do.