1540.33 – Hattie's Age in 1900

We need to look at the exact multiples of 29 in the 1800's. One of them is the year of Hattie's birth. There are three possibilities:

$$\begin{align*}29 \times 63 &= 1827 \\29 \times 64 &= 1856 \\29 \times 65 &= 1885\end{align*}$$

That's all there are.

If she was born in 1827, then she died in $1827 + 63 = 1890$. That is too soon. If she was born in 1856, then she died in $1856 + 64 = 1920$. That works. If she was born in 1885, then she died in $1885 + 65 = 1950$. That also works.

So Hattie was either 44 or 15 in 1900.