The main challenge in this design was to have a bathroom in each bedroom in addition to the guest bathroom.
I tried to put them in the closest place to the current drain. (Bathroom and kitchen drain). It is possible to use the kitchen drain for the bathroom. But it must be implemented in detail and accurately.
Also, I have considered another design with 3 bathrooms that if you didnt want use the kitchen drain for the bathroom, will be usefull (one bathroom for the guest, one of them is shared that have locate close to the two bedroomsof child, and one of them in the master bedroom) . I thought maybe you would prefer this plan or some of changes in that. I've highlighted this changes so you can find them more easily. I have also put the requested plans of the second plan (Plan B) in the DWG files.
I hope you like it...