Bern is (for me the born and bred Bernese) more rural, than properly urban, yet it offers just as much as a big city like Zurich!
Since your wife will be a trailing spouse, she’ll find more distractions in Bern. For instance, there is a very active AWC, which might be her first port of call to get many vital information and recommendations in regard to, say the paediatric doctor/OBGYN/family doctor, playgroups in English (for a start)
https://awcbern.org/
I don’t doubt, that for a new arrival it is the easiest way to find their feet in a new country where you don’t speak the language (yet).
However, I am doing this helping expats job over 20 years.
Out of personal experience, I can say, the biggest danger is to feel too comfy in this expat bubble, surrounded just with other trailing spouses.
It is important to start putting out the feelers quite quickly in parallel too, to guarantee a successful relocation and integration.
Ok, onwards about Bern.
The public transport is 1A in and around the town, as well as the bike lanes, which are well planned throughout the town!
You get everything within a relatively small space, from shopping for anything your heart desires by wandering through the famous arcades over to the shopping centres (if you prefer that kind of thing) in close vicinity of the town and also reachable easily by public transport.
Bern boasts also a very colourful cultural life from opera to theatre to exhibitions, various museums, many traditional customs from the Carneval ( Bärner Fasnacht) in spring to onion market (Zibelemärit) in November.
However, the rent as well as the taxes are higher in town, so it'd pay to look into moving to the surrounding suburbs. Hence my suggestion yesterday to look into Belp, for example.
Lower taxes, cheaper rent, away from the fray, less noise and traffic, yet within a 15min train ride your smack bang in the middle of the city. Belp is south east of the capital.
Thun, is just as charming, but much smaller than Bern. Recommendable, in particular if you are after winter sports opportunities, because you’d be closer to many skiing areas. Also hiking/mountaineering and other such pastimes ask for a basis like Thun. The lake is amazing and there are many ways to take a stroll around the harbour of Thun. Bern, again is only about a 30 min train ride away.
If you are looking north-west, there are also suburbs worth looking into and again Bern is easily reachable with the super public transport system with connections at least every ten minutes (depending on the village).