It is difficult to be precise about later phonological development as the methods of this development differ from child to child.
Command of all the vowels is achieved before the consonants.
By 2 and a half, the average child has learnt and mastered all of the vowels and 2/3
of the consonants.
At 4, the child is likely to only be having difficulty with a few
consonants.
The child may be 6/7 years old when they're confident in using all vowels and
consonants.
Consonants are first used correctly at the beginning of words, whilst those at the end prove more difficult. For example, /p/ and
/b/ will be easier to pronounce in 'push' and 'bush' rather than 'rip' or 'rib'.
In general, sounds that occur frequently in a large number of words will be acquired before sounds used less frequently.
To make words easier to say, children simplify their pronunciation in certain ways.