14 year old dd just told me she thinks she's bi

[wellies]

...and I'm not sure how to help her.

She's been very down and moody for months/a year. Assorted problems with school attendance and her emotional well being.
This evening she's been out with friends, come home and had a HUGE tantrum eventually calming down and with me asking what's going on she said there was something she wanted to tell me - after some angst she wrote on a note 'I'm Bisexual'. She says she doesn't even know if she is or what's going on but she feels as though this is the best way to describe her turmoil.

I told her that made no difference to my love for her or how I'll treat her and she has asked me not to tell anyone, even dh. She doesn't want me to mention it again.

Have I handled it right? What else can I offer if she ever talks to me again.

Just keep being you. Reassure her that you love her no matter what, mention it again in a few days when she's calmer that you have heard what she's trying to tell you.
And just ask her what she needs from you. At least as a starting point for another conversation about it.
A

This does sound fairly normal for 14

Normal as in being uncertain of emotions, attachments etc?

Sounds like you did the right thing. Let her know that you are available for her to talk to whenever she needs to. 14 is a confusing age - they think they are adults and they definitely are not! If she knows you love and support her regardless, then that gives her the support she needs at this point as she tries to sort out her own sexuality.

I'm not sure you need to offer her anything more than your love.
Business as usual.
She's 14.Everything is a drama.

My dd is almost 15 and identifies as bisexual. I don't think it gives her particular anguish though, and it's something we've know about for quite a while. I'm not totally sure whether my dd will end up having mostly relationships with girls or boys at this point - it may depend entirely on who she meets or her preferences may settle down one way or another (or go on being a bit changable).

Although it seems like a fairly straightforward thing, to fancy both boys and girls I don't think it is that easy as there is a fair amount of prejudiced from both the gay and straight communities. dd has complained that people who are bi can be seen as playing gay, denying that they are gay, promiscuous etc.

I think that the issue here is that the dd sounds as if she doesn't think that being bi is OK as she's obviously pretty unhappy at he moment and rightly or wrongly thinks that is associated with her sexuality.

I'd try and create opportunities to talk, so time when the two of you (or another trusted adult) are together and conversations can happen naturally. Whether that's car journeys, a mutual hobby or just going out to coffee from time to time.

Think about resources your dd can access. My dd and I really like reading so I looked for books with central characters that were gay so we could talk about the storylines. There are websites too, but we've not used them so much.