Adding a new maltese to our existing maltese

Question
We have a 15 month old female, spayed maltese named Chloe that we have had in our home since she was 4 months old. My household consists of just my husband and me - no children, but that may eventually change.  We both work but she gets lots of attention when we are home and a dog walker to come twice a day to spend 2 hours with her total to she is not alone too long, plus my mother flies into town once a month just to give her some more company.  She is my little princess - really a good girl, perfectly potty trained and affectionate and I love her madly.  She does have some separation anxiety, which is helped with a crate and a chew toy.  She loves treats and praise and is so intelligent and strong willed in a charming sort of way.  
I am considering adopting a 5 and a half month old male maltese who comes from the same breeder as my Chloe and I understand is genetically her cousin.  I am considering this for two reasons.  First of all, I have met the dog and fell in love with him and would love to have another dog in our home and we love the maltese breed and we think it would be so fun if they got along to watch them play together.  Part of me feels good about him coming from the same breeder.  But really the most important determination for me is whether or not this is healthy for Chloe.  I feel like she may benefit from having a playmate with her furing the day to keep her more entertained when we are gone.  Since she does have a bit of a superiority complex (no matter how much I practice being the "pack leader") and so I suspect adding a female to the house will create more jealousy and competition than a male, as long as he is also fixed.  Recognizing this will cause a few weeks of adjusting for her, is this a good idea or should we just stick with the one dog?

Answer
What a lovely idea adopting another dog,
Well let me first start by saying wow, if anyone should be responsible for two dogs its you you seem so sorted and very organised if seems your maltese has a lovely environment to live in and recieved regular exercise and affection.
I dont see why you should not adopt another however i suggest to please, take a few weeks from work to get them used to each other, when buying new toys and treats buy for both to avoid dominance. also stay in your routine with your dog walker as then they are both ready and in their rountine for when you go back to work. also try leaving them on their own for short periods to see how they get on when your not there. Maltese love their owners and they love affection my maltese seems as you describe yours lol he runs our house and makes our day but maltese are used to company so another dog may be just what you need just be prepared for more work but hopefully double the fun, love and affection. Also exercise the dogs together this is when they truly bond together.
Good luck please let me know how you get on.
One dog is never enough lol.