I have been looking for this book for a long while. I remember being charmed by it when I was 8 - so 2000. In England, UK if it helps. The cover was a turquoise green colour. Some plot points I can recall:
- Either set on the moon, or heavily featured the moon
- Main character was a young woman named Tipperary (the song 'The Way to Tipperary' featured heavily in the story, her mother used to sing it as a lullaby)
- She had adopted a baby boy (at least, I don't think he was biologically hers) who was either an alien or an advanced human - he was very intelligent and could talk clearly, but still an infant
- His catchphrase was 'holy moly' and this was also his nickname
- Tipperary had a bad relationship with her mother because of the baby
- Tipperary had an ex who was obnoxious and who showed up and kick-started the plot (can't remember details)
- Tipperary, the baby, and possibly a dog, lived in a campervan and travelled around a lot, possibly on the moon
- I am so sure the phrase 'holy moly' featured in the title but I'm not finding anything on Google...
Despite remembering weird little details, I can't find any info on this book! Please help if you can, I'd love to read it again, it had such a delightful tone and I'm sure there were more in the series.