Mel, I wouldn't include the bit "I am the mother of 3 children."
What is it the retailer of? Do you have any experience with that?
The cover letter is to sell yourself, I am ....personality traits that bosses look for that they can't see in a resume.
Also, that their employment appeals to you. Just an example but lets say a ladies clothing store, "I pride myself on looking professional/great/insert your own adjective here and I belive that I will be an asset to your team".
Do you know anything about their company that you could throw in there?
HTH