The third dose she spat out into a cup of water.
The fourth dose went down - while we held her nose and tipped her head back.
Subsequent doses have gone down easily, accompanied by laughter.
Here's the (new and improved) procedure for getting her to take her medicine:
• Cheer, "Swallow fast! Swallow fast!" as you put the penicillin in her mouth.
• Hand her a cup of milk, so she can take a big swig.
• Produce an enormous box of Godiva chocolates and let her choose one.
Works like a charm.