Some people swear on ribena or honey to mask the taste. I prefer to give it plain, as that goes in one fell swoop and then give something stronger tasting like ribena afterwards to wash the awful taste away. It takes some practice and experience to learn to handle an uncooperative piggy! They tend to put up more of a fight when they feel that they can get away with it. Often, it can take some patience and persistence.
If you are alone, you can try to lift her on her feet, her back against your chest so she has only got limited space for manoeuvring her head around.
Alternatively, you can try to fix her between your thighs (if necessary wrapped up), so you have got both hands free to stabilise her head and get the meds in behind her front teeth. If you try the second method, make sure that her head is always above her body.