Though you get her assessed by a speech therapist, but she is just 18-month old, and you should give her a little more time. Some kids start speaking clearly a little late. Make her practise the words she has problems in pronouncing, and do not worry as she is in the phase of learning new words and picking them up. Think yourself about learning new language and think how many times you would fumble and forget. So, give her time. :)
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