This is difficult because you don't know what she'll be interested in when she's older. She may return to collecting what she loved as a child (like most of us here on the Arena), or she might not care about childhood toys. You could always buy the pony and hide it away. She'll probably forget about it in time. Wait until she's in her 20s and see if she starts collecting again. If so, it would be such a great gift to give her. If not, you can sell it. If it's HTF now, it will definitely still be hard to find 15 years from now!