Connecting cell phones from other carriers to mifi

[mobilemom]

We have just received our Mifi.  I couldn't be happier with the signal and speed.  The 2G/3G aircard (from another carier)  was as bad as dial-up. We live in a very rural area, so our options are few.   I have cell phone service through another company.  I noticed that my daughters cell is picking up the signal.  If she connects to the Mifi, will it affect her cell phone bill?  She does not have a data plan. I have an Iphone with a data plan.  Will I be getting some hidden charge from my carrier for connecting to the Mifi wifi?  The Mifi is much faster than my data plan.  Our cell phone carier doesn't pick up the 3G net work where we live it shows up as 2G.  I hope this makes sense.

[#2]

When you connect another cell phone to your MIFI, you are connecting via WIFI.  These cell phones will be connected to the internet via the MIFI and will be using some of your 5G monthly data allotment for the MIFI.