"I am a single mother of two twin boys and I am bilingual (English / Latvian) and live in Latvia. I want my kids to grow up bilingual as well, but as my own family language was always Latvian (I grew up in the USA), I can't imagine using anything else but Latvian in the home. How else can I ensure my kids grow up fluent in English as well?"
As a single parent you can basically do one of three things -- speak the minority language to the children, rely on outside sources, or slightly modify your bilingual ambitions.
Bite the bullet
Could you overcome your own reluctance to speak the minority language to the children? Even if you are not initially comfortable, doing so would be the safest road to success; it will only get easier over time -- guaranteed! Maybe 'sacrificing' your own comfort for the sake of your child's languages would be worth it after all? It ultimately depends on how strongly you feel about multilingualism.
Even so, some single parents ask themselves if the amount of foreign language they speak to their children will be enough. Sometimes they work long hours and doubt if the little time they spend with their kids is sufficient. Most likely it is. In a one-parent household, the single parent retains extraordinary importance to the child who will be highly motivated to learn that language -- despite less than optimal exposure.
Another parent, Ute in Manchester, UK, describes how she (German) and her husband (English) separated and she wonders how to handle her move back to Germany. The first three years she had raised her daughter with herself speaking German and her ex-husband speaking English, while living in the UK.
"I would still like my daughter to keep her English, now that we are in Germany. But, was not too keen about switching the language I've used to her all her life, especially on top of all the other changes in her life right now. However, I decided that if I ease her into it, once things get settled, she'll be fine. In the end, I truly believe that the change is not going to be that upsetting, and will easily be outweighed by her lifelong advantage being bilingual."
The other option is to rely on outside sources to provide the foreign language. Those sources can include a nanny, an au-pair, or an immersion daycare. The key is consistency over a long period of time. Three full days per week, or five half days are good benchmarks of 'enough' external esposure. But, as with all things language related, it is highly individual. When the kids start school, maybe you can find a bilingual school for your languages; regardless you'll be responsible for providing a fair amount of outside language sources up until then. If you take this path, there will be extra effort (and cost) in ensuring that someone else speaks the foreign language on a fairly consistent basis.
Rebecca in Portland, Oregon, realizes she has her work cut out for her:
"I am a single mother who has been raising my 16-month old daughter bilingually (Spanish / English) since I returned to work as a university professor when she was 2 months old. Our home language is English and her daycare to date has been Spanish only. I'll try my utmost to maintain this through school or if I don't find a bilingual school I'll get either a tutor, find a playgroup or even consider renting out a room to a Spanish-speaking student."
Change the expectations
The third option is to set slightly lower goals and provide a limited amount of exposure (read some books and maybe watch TV in the second language) to allow your children to gain some understanding. That way you don't have to worry about speaking another language yourself or finding enough external resources to provide sufficient interaction in the minority language. With occasional exposure, the child will start picking up some of the language, and perhaps will even understand it relatively well after a few years. And, that is excellent. Remember that passive knowledge is much easier to turn into active usage later in life than it would be starting from scratch. However, it would be unfair to expect the child to actually speak with such limited interaction.
As they say, 'the proof is in the pudding,' and single parents have raise multilingual children successfully in all parts of the world and continue to do so. Whichever approach you choose is fine, and hats off to all of you!