I am a German citizen living in Germany and my mother is Russian citizen living in Russia. We would like to visit UK together as tourists just for 10 days or so. Is it possible and preferable for her to get EEA family permit rather than UK visitor visa for this purpose? I think UK consulate might refuse her visitor visa because of her age, etc. She does not have any EU residence card or whatsoever. Anyway, what is the time frame for getting EEA family permit? Thanks in advance.
Your mother qualifies for an EEA family permit to travel with you to the UK only if she is dependent on you. If she is not, then she will need a standard visitor visa.
The EEA family permit application is supposed to be decided "quickly"; it shouldn't take more than a week or two. If you have evidence that she is dependent on you, but the decision isn't clear, it might take a bit longer.