Perhaps just the ancestors of Barbie dolls?
Had they been dolls, they would have been intended to be used by children.
The first supposition might be supported by the fact that carving any of these would have required much work, which might have not been justified for just making toys.
On the other hand it is easier to imagine children playing with such small statues than a busy adult using them for any purpose. It is unlikely that the kind of dwellings that may have existed at that time included any part that could have been decorated with such figures.
The article contains the supposition that they may have been used as some kind of home guardians, but the choice of a small feisty female figure does not seem very appropriate for such a role (instead of a more scary guardian).
Perhaps they could have been owned by some shamans who used them in some rituals and they were small to be easily carried in their luggage, but being just toys for children seems an equally likely possibility.
Given that these figurines were being produced for over 10k years with a global distribution, I'm gonna go out on a limb and suggest that multiple mutually exclusive interpretations could have been true in different places and times.
And, hell, Barbie. In the last 100 years, we have observed a doll in the form of an adult woman go from being successfully marketed to adult men, to being successfully marketed to young girls. Why would we assume these Venus figurines had a single purpose?
Emphasizing the fertility in the statues is a reason to believe that they could have been intended for use in some rituals or as good-luck charms, but it certainly would not have been a reason to censor their use by children who would have been habitually exposed to nudity, unlike today.