When working on taming a pet bird, a person must pay attention the bird's body language and to be able to properly interpret behaviour and the warning signs coming from the pet bird, this is done in order to minimize negative reactions, like biting.
It's also important to realize that no amount of training will be full proof and that budgies can bite at any given point in time and as such we must be careful and not purposely expose the most sensitive areas, especially the eyes. This is where common sense should play a role.
If Ibi is biting your face and harming you in the process (no gentle nibbling/preening), then she is responding negatively to your advances and closer interaction.
This is her way of telling you to back off and not kiss her/invade her personal space and safe boundaries.
What do you mean by teasing her? Maybe the way you have been playing with her have been sending the wrong message and she biting as a consequence.
In order to improve the behaviour, you can start by using positive reinforcement techniques where you will reward Ibi's good behaviour.
It might be good if you reviewed the information on the stickies at the Taming and Bonding section.
You can start with these links: