Awwww; you must be one of them 1st time mommy's.
Let me ask you a question; when your students act out in class do you have a solution to counter it other then sending them to the principal's office. If so then you have the ability to desipline. Now I understand that your students are much older then your daughter, but that same struness should be applied. As of right now, your daughter is running the show and I'm sure in your classroom you run the show. Bottomline, apply that firm tactic you use in class at home. 14 months, oh she know just what she is doing and she is playing you like a puppet. For goodness sakes STOP PICKING HER UP AND HOLDING HER!!! She is soiled and by time she's 2 she will be rotten and that is very hard to break. Let her cry, my grandmother use to say "the more you cry, the less you pee". Let her cry, so what. Go on and do whatever it is that you need to do around the house. As far as her not walking, I agree that it's because of the holding. Put her butt in a walker and let her do her thing. When it's time to read, play, watch tv, eat, put her in something other than your lap. And when you do, don't just pick her up and put her in the walker or in the highchair, hold her from behind and kind of help her to clime into it. This will also help with transtioning into becoming independent. Same thing with feeding, if you are not already doing it, let her feed herself. The goal here is to give her the space she needs for development. It might hurt your feeling to see her stumble and fall, but knowing she will get up and try again instead of always running to mommy makes it all better.
Hope this helps,
P.