That's pretty common in the early teenage years. You could probably fap to linoleum.
Myself, God. In those early days I could fap to just about anything with revealing clothing. I mean, sure there was my dad's rather epic porno mag collection, but there was also the JC Penny catalog, Victoria's Secret catalog, SI swimsuit issue (that was an early fap favorite) and hell, even my mom's old art history textbooks.