@Emerald237
I assume that they've talked to you about encouraging language by using what she says. Like:
Her: Bmm
You: Yes, that's right, it's a car.
Her: Bmm
You: That's right. A big car bmmmm
So you're modelling back the word you want her to use, but praising her for what she does say.
Use single words while she's learning. If you give her something name it.
"Drink" or "coat" etc.
Using the words isn't always consistent. Maybe the next time she sees a car she isn't sure it's a car. How does a child know the difference between a car and a van and a lorry etc? They learn, but sometimes get it wrong. Maybe she's a bit more cautious about it if she isn't sure. Or maybe she just didn't want to say it.
When she makes a sound, even if it's nothing like the word you can say "well done! it's a car" excitedly, and then she may think speaking is a great thing.
I know someone who fed their dc 12 cupcakes in a day the day her dd learnt to say "cake" :)
If she likes books then point to things in books "there's a flower" and see if she will find them too. "Can you find a flower?" and then point to them-you can use her finger to do that if she is happy for you to do that.
Try and make sure she's on your level and you can get eye contact ideally.
Use a few signs. They help with communication and encourage them to think about communicating. I used food, drink, more, thank you as basic signs. One of mine did lots more, but those three were just good for them to be able to use.
And she almost certainly will just have an explosion of language and catch up without intervention. However keep her on the waiting list because it can be quite long.
I've told people before that my oldest was a good talker, and I had a friend who had a dd almost exactly the same age. We lost contact around about when they were 2yo, at which point dd was saying full complicated sentences and her dd was just beginning SALT and had no more than 2 words. We met up again about 2 years later and no one would have been able to tell which was the early speaker, and which had had SALT intervention. It was no sign of genius or being amazing; simply just "early talking", which in the long scheme of things doesn't matter-even though it does when you're going through it.
With 40-50 word explosions that's subjective. Some people will hear their child say "ta" as a car passes and note that they can now say "car", and "cars", someone else will not note that they're saying "car" until they pronounce it perfectly and have used it several times in correct circumstances.
Also remember at that age it's also often called "appropriate sounds" rather than words ie bmm for car counts just as much as saying the correct word. So feel free to bark at dogs etc.
Also don't think it's your fault. I know they talk about "talking with your child" and "encouraging language" but really it's as much about your child will learn when they're ready. My friend above worked in early years and knew exactly how to communicate and did so all the time. "Talk lots to her" sounds like they're implying they don't think you are-I don't think they are. It's just telling you to keep going.