BJ, I’m going to guess that part of your daughter’s problem is in your ears rather than in her speech. Let me explain what I mean so you won’t take offense.
As our children begin to talk, we are very forgiving of the sounds they produce. If you don’t believe this, just notice how often you have to ask other children your daughter’s age to repeat one or more words. It’s difficult for you, but not for their parents!
If, when your daughter was just 1, you showed her a picture book and encouraged her to say she word “zebra,” you would have been ecstatic if the word had come out “meea,” “bra,” “tema” or almost any other combination of sounds. As a loving mother you would have excitedly announced, “She can say ‘zebra.’” By the way, “zebra” is not exactly an easy word to pronounce. It has a hard sound called a fricative (“z”) at the beginning and a consonant blend (“br”) at the end.
As your daughter matured, she probably tried to refine her sounds at the same time your ears became more demanding! Both of the examples you give involve that very difficult “z” sound. Make it slowly yourself and feel all the vibrations and pressure necessary to produce it. Not only is it complicated to produce – you can’t see any of the tongue and teeth movements necessary to make it. The “l” sound can’t be seen either, but it’s a lot easier on the vocal mechanism than the “z.” Again, try it for yourself, and you’ll see what I mean.
So in the early months and years, it’s all trial and error with a lot of inevitable error. Were it otherwise, we would not have the expression “baby talk.” The most important task for your daughter in terms of talking is to learn to love language. Talk to her and read to her but don’t constantly correct her pronunciation. In time she will probably make the necessary corrections without any special help.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.