Yes, I completely agree with you. In fact, this sentence is found in Sec 1 and it uses 'did'. I first read it as you did, then I thought that the writer uses 'they' to refer to 'children and mothers'. It is illogical to say that 'they' refers to 'fewer children and mothers' as the sentence will be meaningless then.
Hi, Ahmed_btm—Your proposal here is very interesting, and I've been giving it a lot of thought. The "they" in the "than"-clause doesn't sit well with me on any interpretation in which it is co-referent with the subject of the main clause.
Also, if we replaced "they" with "children and mothers," the sentence would still strike me as grammatically ill-formed. I believe that there is a restriction here whereby, if the second subject is the same, it can't be expressed.
Although I am still doing some research on this matter, I have just thought of a nifty way to demonstrate that the restriction I am talking about is real. Consider the following sentences:
(1a) Fewer people have health problems than animals do.
(1b) Fewer people than animals have health problems.
(1a) and (1b) show that the "than"-clause relates to the comparative term in the subject NP in such a way that, if the predicates of the two clauses are the same, ["than" + subject of the "than"-clause] can be embedded in the subject NP.
Now, in Ahmed Imam Attia's example, the predicate of the main clause is not identical to the predicate of the "than"-clause, so the type of embedding we see in (1b) is not possible.
Nevertheless, the comparative term in the subject NP of the main clause ("fewer") relates to the subject of the "than"-clause, and we may observe the impossibility of the following:
- Fewer people than people . . . .
- Fewer children and mothers than children and mothers . . . .