Golden Retriver is playing too hrd

Question
We brought in our family 2 weeks ago, a year old female Golden Retriever. Our smaller dog we have weighs 10 pounds and is a Peek-a-poo. I have noticed that our Peek-a-poo is scared to go outside and play with our new Golden Retriever Sadie. Sadie tends to get too rough and Snuggles, our Peek-a-poo wants to play, But Sadie is too rough with her. Also, our peek-a-poo is to the point now, she is almost afraid to go outside and potty or play. She goes outside, but is quick to get back on the patio. Half the time, she doesn't pee outside and I have alot of trouble, just getting her to potty outside. I guess, I have a two part question. is there anyway, I can get Sadie our Golden Retriever to play nice with our Peek-a-poo(snuggles) to where they both can play and Snuggles gets over her fear of getting hurt? Both in playing and in potty time. I'm not sure if it is a time thing or something I can teach and if so, how do I teach that to them?

Answer
For now take Snuggles out on leash to potty.  Walk her around until she goes.  

Most of what I see are older dogs and puppies.  Usually the older dogs are surpassingly gentle.  If not, you need to break it up, separating them or a few minutes.  If you are consistent about this, the Golden should catch on before long.  It may be used to playing with larger dogs.