Two agents interested in seeing my manuscript -- etiquette advice?

Hi -- I believe this has been covered to some extent in a thread I read below, but I believe my case might be slightly different, so I'd appreciate any feedback.

Six months ago, I received a response to my query from Jennifer DeChiara asking to see my full manuscript. I sent it immediately and waited patiently -- her website mentions that it takes about three months to respond, so after six months I sent her a polite letter asking if she had reached a decision on my manuscript yet.

I haven't heard from Jennifer DeChiara yet, but today I got a response to another one of my queries from Liza Pulitzer Voges asking to see my full manuscript.

I haven't promised either agent exclusivity and stated in my query letter that the query was being submitted to multiple agents. I'm still curious though -- is there any type of etiquette I should follow in this situation? Both are reputable children's book agents according to my research and I'd be lucky if either one of them represented me -- but I wouldn't want to alienate either one.

Thanks!

Thanks for the advice! And to answer a question -- yes, I did include a SASE in both my note to DeChiara six months ago and the note I sent to her last week. Your suggestions sound fair and professional -- I think I'll follow up on that by informing DeChiara of what's going on.

Thanks for the advice again you guys! I ended up sending an e-mail to Jennifer DeChiara (the first agent) and received a very prompt e-mail from her letting me know it was okay to send to the other agent and also to forward her my manuscript via e-mail so she could get to it sooner.

So it turned out for the best!