Telling my family my partner is transgender

I apologize if this is long, I tend to post wordy things.

For context: I am a bisexual woman, and I've known that for YEARS at this point. My relatives (at least, the ones I see regularly that matter), all know this and they have a generally somewhere between neutral, bad, and indifferent view of it. They've never outright judged me for it but it's not a freely open conversation we have either. They still love me and their support hasn't overly changed but I'm not sure how they'll react to this news.

My family has known my "boyfriend" for over a year now. My mom is actually the one that set up my partner and I! However, just a little after my partner and I's one-year anniversary, she told me that she was an MTF transgender person. Due to work complications and not being able to afford a therapist, she does not plan to medically transition anytime soon. However, she eventually wants to socially transition and live as a girl as much as she possibly can outside of the workplace.

I don't personally have an issue with this. I've seen it coming from a mile away. She came out to me as genderfluid, and then bigender prior to her coming out as trans. I helped her pick girl clothes and makeup shopping and let her go out in public with me as a woman. However, all of this has been behind closed doors, and because I still live with my Grandma, it impacted whether she can come over to my house or not and it caused a lot of stress in my life.

It took me seven years to come out as bisexual to my family, and now I feel like I'm back in the closet again. I want my family to know so bad because some of them see me and will see her frequently. I want them at minimum to be okay with seeing her in feminine clothing or makeup or something if possible. She hasn't changed her name yet and she's pronoun indifferent for now (but strongly prefers she) simply because she just came out to her mom not that long ago and the whole family needs a bit to process.

My family loves her so far, and they love her as my "boyfriend". However, I don't know how they will react to figuring out she's transgender and at minimum wants to socially transition. I have relatives from all political backgrounds and ideologies and some were nicer to me about my coming out than others... I also don't want to be the one that immediately comes out to them about it and i want her there for me so she can answer questions and have her side of the story. I just don't want to live in fear like that forever again- and I want to stay with my partner even through this.

 

Hi! Thanks for reaching out!
I planned on having my partner be the one to reveal this aspect of our relationship to family. I don't necessarily want to be the one to do it outright. I apologize for the confusion. The issue is: My partner told me "whenever you're ready for me to tell, I'll tell." I'll never EVER be ready to tell them. I have a lot of anxiety surrounding family relations because I've technically been disowned before by one of them (not for being LGBT, but for reasons completely unrelated to me...), and I have a strong fear of abandonment and irrational fear of being disowned or emotionally neglected because of it. I have to be the one that gets the ball rolling with that side, but I don't know how to be the one to do that.

My aunt already knows and she was accepting of it, but she only knows part of the story. We want to discuss it in full with her in the future.

My girlfriend knows that this is eating me apart, and she even joked that I'm taking her coming out "worse than she did." She said she'd be wiling to discuss when I'm ready, and she knows I'll never be ready...but it's weird because she doesn't want to rush me, but because I know I'll never be ready I want to get it over with ASAP so I can just process and move on from it...