If you can find amoxycillin then the dosage you need is 20mg of pure amoxycillin per kg (2.2lb) live weight of your bird. It's only approximate, so calculate around 10mg per 1lb of bird. Tablets for humans usually come in large doses - 500mg or more, and you are only going to need around 40mg per day, if your bird is around 4lb.
The best thing to do is therefore to break a tablet in half, giving you 250mg, crush it into powder, and sprinkle it into 50ml of water. If you mix it well, and give her 10ml of water a day then you are giving her a 50mg dose, which is about right for a 4lb bird. You need to make sure that she takes it all - either by dripping it onto something that she will eat (a piece of bread, some boiled rice, mixed in with cooked egg etc), or by syringing it drop by drop onto her beak and letting her swallow it. (Don't try and force it down her throat - you can accidentally force water into her lungs and that would kill her.)
If you don't want to use water then sprinkle the powder onto food, and divide it into the right number of portions to give 10mg per 1lb weight of your bird per day.
Good luck with your girl - let us know how you get on.
The best thing to do is therefore to break a tablet in half, giving you 250mg, crush it into powder, and sprinkle it into 50ml of water. If you mix it well, and give her 10ml of water a day then you are giving her a 50mg dose, which is about right for a 4lb bird. You need to make sure that she takes it all - either by dripping it onto something that she will eat (a piece of bread, some boiled rice, mixed in with cooked egg etc), or by syringing it drop by drop onto her beak and letting her swallow it. (Don't try and force it down her throat - you can accidentally force water into her lungs and that would kill her.)
If you don't want to use water then sprinkle the powder onto food, and divide it into the right number of portions to give 10mg per 1lb weight of your bird per day.
Good luck with your girl - let us know how you get on.