Potty training puppy #2...

Toby's "little sister" will be joining our family in a couple of weeks. Toby is 14 months old now. I'm assuming potty training the new puppy will be easier, since she can follow his lead, but I'm sure there will be a lot of indoor accidents too. Can we expect Toby (who is completely potty trained) to regress a little when the new upstart pees on his indoor territory?

Also, and I'm not sure why except that it was winter and easier for everyone concerned, Toby will only go to the bathroom on a black rubber mat that's right outside our back door. (We keep it very clean and replace it frequently, and it's not really a problem.) Should we get the puppy her own mat to keep her from using his? (I expect we'll be pottying them together and it's only big enough for one dog at a time.)

Am I overanalyzing the whole situation? Feel free to be brutally frank! :mrgreen:

Thanks in advance!