You probably need to conjugate 'esquiar' to ustedes form but that depends on the form you guys are in like: Present or Past Pogressive, Preterite...etc.
Answer: I believe its ellas, if it's incorrect i'm sorry
Yo <em>estoy hablando</em> con Miguelito.
Estar = not done yet, but will be done...
vs.
Estoy = in the current process of...
Hablo = Speak
vs.
Hablando = Speaking
In this sentence we use estoy and hablando because it is current.
Hope this helps!~
