Yes get her hearing tested to rule that out as a problem.
Your GP can refer her. From what you say, she does need speech therapy.
In the meantime, there are things you can do to help.
We use loads of signs to help my son say sounds.
eg. Get her looking in the mirror and practise being a goofy rabbit for the 'f' sound.
Try and get her to play a 'hissing' snake for the s sound, using her finger to pretend to be a snake.
For the 'k/c' sound, what works for my son is pretending he is hitting an imaginary hammer at the same time as shouting the 'k' sound from the back of the throat.
Put jam behind her top front teeth to help her put her tongue in the right place to say the 'l' sound.
Also, get her blowing bubbles, licking her lips, touching her nose with her tongue, talking, singing, making animal sounds.