If I use an old iPhone 4s as an iPod can I use dictation and Siri?

My mom is upgrading to a new iPhone. I want an iPod, so my mom said that that I can use her iPhone 4s as an iPod touch. If I put the sim card of the new iPhone into the iPhone 4s(I know I need a sim card; my mom is putting the sim card in her iPhone 4s in her new iPhone so she can have her phone number and stuff...), will I have Siri and dictation(talk-speech on the keyboard)? I will use her old iPhone 4s as an iPod touch, for games and music, etc... Her iPhone 4s is not jailbroken or anything like that.