My daughter is 3.5 years old. She doesn't sound few letters like 'L' but 'N' instead. But I believe she will learn that by time.
However few weeks back I noticed that she speaks from her nose (nasal speech). The way she speaks words ending with 'N' or 'M' are different. Eg. she says
Rumb instead of
Is there any practice or speech therapy we can bring in daily practice to improve her way of speaking?