I just came back on Saturday. I did take my 18-200 with me. That being said, it is a clunker and made the camera pretty heavy! I didn't take any other lenses to the park (MK) though and didn't have to worry about changing anything out or a heavy bag. That was nice. I was shooting a big family and 3 kids under 5 too, so the zoom was kind of nice.
I have a 50 and did wish I had taken that for the amazing bokeh it presents and the fact that it is faster and better in low light. So I think your 30 will be great. You can always crop after the fact.
Side note - I hope you have a filter on the end of your lenses!! My 2 year old knocked my camera off of the stroller a second after I sat it there to open my bag.

It landed directly on the end of the lens. I completely had a heart attack, since it is a pricey lens. The lens cap was jammed in and the filter was cracked. Once I was able to unscrew the filter, the lens itself was completey fine! I could not believe it. I have to get a replacement filter ASAP, but I was so thankful the lens was okay! 
I have a 50 and did wish I had taken that for the amazing bokeh it presents and the fact that it is faster and better in low light. So I think your 30 will be great. You can always crop after the fact.
Side note - I hope you have a filter on the end of your lenses!! My 2 year old knocked my camera off of the stroller a second after I sat it there to open my bag.



