Sure.
Becoming a verified performer on OF is a high barrier to entry - you need to provide not only legal identification, you also need to provide bank account information, and then wait for approval from OF. This eliminates a large amount of people from the pool of amateurs.
Having no knowledge of her personal life, she might be unwilling/unable to work with professional studios and the talent they could offer her there.
Additionally, there are likely circumstances we don't know about with Dahlia and her partner (providing support beyond just collaboration on OF content - housing, possible childcare, among any number of other things).
There are plenty of reasons beyond what I've listed above.
Doesn't really do any good to burn energy wishing she would perform with other talent. She hasn't so far, and that's all we have to go off of. She might change that stance in the future, but there are barriers (known and unknown) that she is unwilling to overcome at this point.