Children do not learn all speech sounds at once. They build them up over several years, starting with sounds that are easier to see and make, like those made with the lips, and adding more complex ones later.
Sounds such as R, SH, S and L in English are among those that often take longer. Children growing up with more than one language may develop sounds in each language at a different pace, which is common and not a problem in itself.
Every child is different
Ranges are wide. Comparing one child with a sibling or a classmate rarely tells you much. What matters more is whether speech is gradually becoming clearer and whether the child can make themselves understood.
Bilingual children
Speaking Urdu and English does not cause speech difficulties. A bilingual child may sometimes mix sounds between languages, which is a normal part of learning two sound systems.