Hello and welcome along to the foum
Here is my opinion of your situation - Your boxer girl is only 13 months old and is still very much a baby herself - I would wait until she is over 2 years of age before re thinking your situation.
The DLRC ( OH no how do I put this politely??? LOL ) <<<Wouldnt be on the post I made if this were real LOL
Hmmm ok would not have a clue about explaining the Dog lovers club thing without offending the original poster....
Being registered with the DLRC doesnt always mean that your dog is of breed standard or that his/hers pedigree is 100% correct. You would be better off buying a KC registered boxer girl and then looking into breeding by contacting breeders and breed clubs and also reading up as much as you can of your chosen breed and also the whole breeding process.
If you want another dog like your boxer girl, why not contact a reputable breeder and buy another pup???
Also before breeding any dog it is advisable to have them health screened, you can look into this if you contact a boxer club too....
Having pups b'cos you think it would be fun or the kids would love it isnt really a good enough reason to go into breeding her, I understand that you would like to have a pup for yourself but what about the other pups? Have you got homes set up for them?
Could you take any of them back if you needed to? Can you afford to breed from your girl in the correct way? Can you devote weeks and weeks of your time to care for mum and babies, these are just some of the questions you need to ask your self before breeding from your girl...

Oh I give up.....LOL....its hard to explain the reasons to people who just want to have a litter out of Flossy cos shes lovely .....and dont understand the bigger picture of breeding healthy, tested, breed standard dogs......
Come on - who can explain the whole situation to this person without upsetting anyone?????
Good post - lets see what comes of it LOL