I have to disagree. Lauterbrunnen is just as pretty and in my opinion has more to offer overall convenience wise. Every time I visit the area (going for the 5th time on Saturday) whilst wengen is pretty and has the beauty of very little traffic apart from the motorised cars it always feel as if it's waiting to wake up. I always go at this time so it's early season but for me LB has more character and with a young child I'd say you'd be better off as you have more choice. Wengen is great to get to Kleine Scheidegg and Jungfrau but there are lots of other places to go which are better accessed from Lauterbrunnen. I know it's only a short journey but having done that journey a few times with a screaming toddler it can feel like forever especially when on the more scenic routes people are less tolerant of their peace being destroyed. Every time we got on the mountain train whether it was popping ears maybe or just the amount of people on the train our nephew got really upset.
And when people have paid a lot to see the scenery they are not overjoyed with you and it's so stressful for the parents.
I'm not saying don't go up the mountain, I just think personally if you stay lower down you have more options on noisier trains which may make your holiday more relaxed when you're not worried about what other travellers think.. Either villlage is lovely but for me LB has more going on and you can walk to lots of places on flat ground without having to get on a train. Kids also seem fascinated with the fast flowing water through the village and at the nearby Staubbach which got our nephew off to sleep many nights. We also felt as did his parents that on the couple of nights we ate in the village restaurants with him asleep in his pushchair gave the a much needed night out without any hassle. It was warm enough to sit outside and he slept beside us whilst we had a lovely meal.
You can also walk along to Trummelbach from here, really flat and beautiful scenery and lots of footpaths with no traffic. Wengen being higher up means you have great options for walks up or down but not many on flat ground and the path back to Wengen is far too steep to take a baby unless you have a backpack carrier.
If you don't want to do the hiking trials, and sounds as if you just want to relax in beautiful scenery I'd pick Lauterbrunnen. More choice and less silence.
Edited: 1:44 am, May 25, 2012