"Voice" Some help with Japanese Translating?

I'm a mangaka. I'm currently working on my prima opus, doing everything myself because I'm wayyy too poor to hire anyone. This includes translating. I'm doing (okay) so far, but I know I'm struggling with conveying voice. -- By voice I mean the same as with English writing. Different people speak differently, and writing that out makes a story more immersive. -- So an example is how a little girl talks compared to her grandfather. The little girl uses dictionary forms, no formality, and has little concept of particles whereas the old man may speak very formally and use a lot of command statements that would be seen as rude if said by anyone other than an elder. I'm hoping that if I hit a snag, I can post some of the phrases here and someone will be kind enough to take a red pen of death to it so it looks right?

I mean, if I'm getting this right, you mean, to better convey their character/personality through their speech? Only kind of characters I can efficiently do are evil bastards who like to give speeches, and those witty ones that we all love. I'm kinda at a loss, and I feel like I should have just kept my mouth shut since I most likely won't be of any help... But I feel like I should support you somehow, now that I've gone and involved my nosy self. You have a Patreon?

Does this sound like an old woman talking to you? "分かるくれてありがとうね、ヒヤチセイ先生。 きちんと餌をあげてね着替ねさせたら、すぐにご紹介しますね。 でも、この変な色のたてがみは目立ちすぎね…"