I'm sorry! My website URL is http://www.estrellaweb.nl
At the moment you will see a Twitter timeline, but after posting this, I found out I could customise the 'standaard' Twitter widget, which gives me the same options.
But, I still would prefer using the Jetpack Twitter widget. If you prefer, I can put back the Jetpack timeline for a while, so you can see how it refuses to work. Please let me know!