Never seen it. The few somali girls married to ajanabi never had kids with somali guys
Its because if someone chooses to race mix, which is halal, but if they do they typically have particular tastes which is why they didn't inmarry to their own people.
If a somali woman marries an ajnabi she probably isn't that attracted to somali men, its illogical that she would hop from a somali man to an ajnabi because if she liked somalis she would stick with them.
It could happen the other way around though, like if a somali woman married a pakistani, got abused, then married a somali man.