
I would wait until all the health testing is done. My late Springer was from a working line, and I can tell you she was the miracle pup. All but her, in a litter of 5, died from liver failure before they were two years of age.
Spaniels also have a hereditary condition called Rage Syndrom. Its epilepsy where the seizure causes rage. They attack for NO REASON. They do not know what is going on, and do not know that they are attacking. The dog remembers nothing of the agression.
Also, eyes and ears are a big problem in the breed. Others have listed eye problems, but ears are just as bad.
The big ones to worry about are the eyes, epilepsy and liver. Dont know if they have it in the UK, but here we can do a wellness blood profile, which will test at least the liver enzymes, kidney, and thyroid. Here it costs about $100 CAD.
I would hold off, to be honest. The dog will be in season again, and you can do the research of different health issues, and then be more prepared for a litter of pups.