From a mum who had a slow to start talker who is now in speech therapy, please don't keep waiting if you think there is a problem with speech. Talk to your child all the time - read books, hold conversations with them, ask them questions about things - anything that will make them talk back to you. Dont use their baby talk words if they cannot say what something is - use the proper name for it so they learn how to say it themselves. Public waiting lists are long and if you do think that there are issues (any of you) then get a referral and have them assessed and get their name on the waiting list.

For what it's worth, I think that she isn't going too bad, but like with anything there will be those that have more and those that have less words, so you can't really compare children. All you can do it talk talk talk with her and encourage her to talk too - practice animal sounds and names etc, shapes or colours. Anything that will engage her.