I’ll give her the benefit of the doubt that she means legal immigration since illegal immigration is not immigration. Bringing over engineers, and scientists through legal immigration has been a benefit.
If that is what she meant, then yes, she would be correct as usually those folks are screened well beforehand. Most of the folks committing the crimes and costing our nation a trillion or so per year are illegals. The prisons are filled with illegals (but also there is a sizeable population of legal immigrants in prison also who decided joining gangs was more profitable than the jobs they came here for- but the lure of “easy money” can affect everyone, not just legal Immigrants)
I will say though that folks like Obama and Biden just Import people without carefully making sure they are here to work. Obama was big on bringing them into the US, giving them housing, $$ etc, and not requiring them to work. Who knows how many that they approved actually do work and contribute?