From a libertarian point of view, if you aren't promoting legal immigration then you are promoting illegal immigration by default.
I've always thought that a government that has programs to help those learn English is another way of ensuring immigrants integrate and are successful. Other countries do certainly ensure their population know other languages from an early age. In your case your wife was already proficient, but not everyone will have that to rely upon. One of my great-grandmothers could speak four languages, another only spoke Germany/PA Dutch and relied upon my grandfather for translation. My husband often sees how many immigrants are coming for ESL classes at the college, but that relies upon immigrants that already have some kind of support system with family and the financial means. There are many immigrants that won't have that resource.
We often complain that our own kids can't read, write, or speak properly... and I often hear English speaking persons talk down to immigrants whose grasp of English isn't the best or limited (on both sides of the pond) I think English speaking assistance is one thing that the government could help with that is worthwhile. At the very least I think we could find ways to encourage it that are productive.