I'm not sure how to put this into Irish - it's about a wedding party so it's feminine.

And I know myself that it was good because on the eleventh morning, it was going as strong and getting better as it was on the first morning.

Agus tá a fhios agamsa go raibh sí go maith mar gheall a bhí sí ag dul chomh maith agus ag éirí.....

Agus tá a fhíos agamsa go raibh sí go maith mar ar an t-aonú mhaidin déag bhí sí ag dul chomh láidir céanna as an chéad mhaidin, agus ag éirí níos fearr fós (fiú).

I know you say "sí" as "bainis" is feminine, but it kinda sounds weird to me to not to say "sé". Personally I'd use "sé", but I don't know why.

(or tá's 'am héin - as we'd say in Conamara)

Go raibh maith agat