Hi Dar, welcome to the forum. Breeding is not a high priority here as the forum is devoted to cat rescue. That is not to say that there are not people who are members of the forum who breed. There are a few of them. The main reason you will receive a negative response to the idea is that many members see the end result of bad ownership. Many breeds of animal, siamese cats included are adopted by people who do not do the proper research into the characterisitics of the breed and their requirements. So an illinformed siamese purchaser might not realise just how penetrating a siamese voice can be at 3 in the morning or how annoying (to them) the cat's behaviour might become. So they dump it or put it on the free ads and our membership ends up with the cat after it has been through several cycles of hell. Since our primary concern is the wellbeing of the cat, not the owner, we tend to discourage people from breeding their animal since once the animal has left their control they are unable to guarantee it will live a long happy and healthy life. So better not to breed in the first place. Similarly the actual breeding process carries risks as does any pregnancy so the cat who is being used for this purpose is also being placed unnecessarily at risk as a result of the owner's decision.
I strongly recommend you engage in a level of self-examination that includes consideration of the fitness of your queen to breed (does she carry any latent abnormalities or disorders that might be passed to possible kittens?), her state of health. What your motives are for breeding her, whether you are going to be willing to take back any of her offspring that do not fit into their new home or whose owners later find they are unable to keep them, and matters of that sort. Also talk to the breed societies and to your vet.
Good luck with your decision-making process and please let us know what you decide!!