Hi Dargarov -
I share Chantal's concerns for the specified days, but it is because I don't know how able your mother-in -law is, and whether she will handle the hikes.
I assume that you will not be jet lagged, since you are coming from Paris?
What you propose is possible, but you should look carefully at the timetable to figure out options and timing for various choices.
Here are some examples-
At the start -
The fast trains at xx04 and xx34 take 1 hour and 34 or 37 minutes from Bern to Montreux..
In the middel -
On the way to Interlaken, If you leave Montreux on the 1144 Golden Pass train ( MOB Panoramic) you'll get to Interlaken Ost at 1449.
I don't know how long it takes to get to the chocolate place.
Other options for Montreux to Interlaken -
If you take the regular train on the same route, you can leave Montreux at 1253 and get there at 1628.
Other routes are faster. The one through Bern is probably the fastest. The one via Brig and Kandersteg has nice scenery on the leg from Kandersteg.. Don't use the still faster tunnel from Visp.
Google maps says it is a 42 minute walk from Montreux train station to Chillon. Buses take 12 or 13 minutes and may include a 7 minute walk. Mix and match, if you wish, and check out all connection times in the SBB timetable. That's the advanced one at this page ( useful explanations).
or direct :
It is a fairly steep 33 meter descent from the station to the lake level:
map.geo.admin.ch/?topic=ech&lang=en&bgLa yer=ch.swisstopo.pixel karte-farbe&layers=ch.bav.ha ltestellen-oev,ch.swisstopo.swiss tlm3d-wanderwege&layers_visi bility=false,true&E=25 59786.62&N=1142540.13& zoom=9
So, if you catch the 0804, you get to Montreux at 0943. That gives you 2 hours to get to Chillon, look around, and get back to the station. That's what you'd be able to do, but you'd be pushing. Catch an earlier train...0743 0r 0704 and gain time at Montreux. or, don't take the panoramic Golden Pass train at 1144, and gain leeway.
Use the SBB timetable, and test with and without Zweisimmen in the via box.
At the end, there are frequent trains back to Bern, taking 1 hour from IO. Evey half hour until 2000, the once per hour on the hour.
I'd do it.. You children are old enough to move fast when needed. You can do the whole route with minimal walking, by making choices.
Sunday , the 24th-
I think it all fits together acceptably. You can be flexible at Luzern, and take the train instead of the boat from Alpnachstad, if you have to shorten the times.
Luzern Altstadt (old town) is fairly close to the station...if you go to the Lion (Löwendenkmal on this map):
map.geo.admin.ch/?topic=ech&lang=en&bgLa yer=ch.swisstopo.pixel karte-farbe&layers=ch.bav.ha ltestellen-oev,ch.swisstopo.swiss tlm3d-wanderwege&layers_visi bility=false,true&E=26 66404.50&N=1211840.00& zoom=8
you'll have about a 1 km walk, sort of skirting the old town. There are buses or trams for some part of it...don't have details at the moment, but they're available on line. You can shorten your time by not going to the Lion. It's the furthest thing from the station.
Trains to Bern - 1 hour, on the hour. Longer trips at intermediate times.
Friday, the 29th -
You are wise to put the BO at the end. Mid june is a bit chancy for high altitude walks, and they;ll be plenty of snow pack this year. The Mannlichen hike rarely opens before the 15th and it may be days later. It's also good to have a few days in the region, as you are doing, to accommodate the changeable weather.
By the way, the choice of villages is a highly personal thing, but I like Wengen, as do many other forum members:
On the 29th, the first hike you list is easy and no problem. A local nickname for the walk Is the Grannies' Walk.
Of course, Swiss grannies do it uphill ( from KS to M) and at a pace that would leave me panting.;-)
It's a beautiful walk. Photos attached.
There is nothing to see that especially distinguishes Kleine Scheidegg; of course the views and the scenery are really nice.
The stretch to Wengernalp mighty be a bit hard on the knees....Since it is a 187 meter descent in about 2 km of walking. However, if your mother in law walks regularly, she'll probably be OK. I'd not recommend walking all the way to Wengen. We did it once when we were not in shape, on our 50's, and our knees were really tired at the half way point, and sore for a few days afterward. That descent is 800 meters... much more than going to Wengernalp.
Probably not Zürich unless you are interested in museums and shopping.
The other two are nice. I'd also consider Fribourg. The old town by the river is compact but nice. The restaurant au Sauvage is extraordinary. Reservations are desirable, but a Tuesday may be light.
The 30th -
I like to be closer to the airport on the night before I leave. However, my flights to the Sttes always leave in mid- to late morning. aturday means that the morning rush hour will not make problems on the trains, but I'd set my schedule to get to the airport at least 3 hours ahead of flight time. Then you'll not be worried if there is some complication slowing your journey. You'll make with 2 hours at the airport