Rate my list and please be as brutal as you want

Love all except Mariah. I like mariya (MAH-ree-a) though

Tess and Anya are my favourites from your list. Both short but sophisticated. So surprised Jane is getting so much love on here!

Tess - it's a nickname, I think Tessa or Esther are nicer
Helena - lovely, sophisticated. I guess the only question is would you pronounce it 'Hel-enn-a' or 'Hel-ayn-a'? as people have different ways of saying it
Jane - so dull
Mariah - I really like it although unfortunately Mariah Carey will dominate associations for a while
Anya - ok, not a big fan, very common in certain European countries

So my easy winner would be Helena.

Tess is gorgeous. I also like Anya (but prefer Anna). Really like Maria (either pronunciation) too but Mariah (this spelling) is all Carey to me, sorry. Helena I can't warm to although objectively it's a good name. Jane is definitely very retro - would be good to see on a baby.

Tess, always sounds like it should be short for something, I really like Anya, it is not well used and sounds lovely to me. None of the others grab me.

I like Mariah, it was my Irish great-grandmother's name.

Tess is OK but I prefer Tessa

Jane is too boring for me, Helena too snooty

Anya is an ugly word and reminds me of onion.

I really like Tess. I don't really like Mariah. The rest are fine

I like Helena Jane

Not keen on Tess or Mariah

Anya is ok

Love Helena and Jane.

I like Maria, Marie, Mary and Mara. Not Mariah. The h on the end makes it fussy.

Anya is too potato for me.

Anya is lovely and v European if that matters to you? Would work in a number of languages.

Helena is nice and classical-sounding. I like Jane more than I thought I would - it’s actually quite strong.

Not too fussed on Tess which sounds a bit wet to me, sorry. Mariah is a bit show-offy.

Jane not Jayne. Jayne is awful, Jane is lovely.

Tess - beautiful, understated, mentioned a lot on MN lately so likely to see an increase in this years and next years baby name stats
Helena - gorgeous
Jane - see Tess without the popularity increase prediction
Mariah - prefer Maria. But don't think you can use the old pronunciation of Maria as it would confuse people. Not keen on Mariah.
Anya - international vibes. Least favourite.

Jayne not Jane - Jean is also lovely

Tess is my favourite, then Helena. Love both these two.

Then Anya. Nice.

Then Jane. OK.

Not keen on Mariah. But if it was Maria it would move ahead of Anya.

Love Tess - but Tessa better, then she has choices?

Don’t really like any of the others but at a push I’d go for Anya. Prefer Anna.

I love Tess and/or Tessa. Would have been on my list if we had a second girl. Don’t have any strong thoughts one way or the other on the rest of the list.

Tess can also be a nn for Esther, as said it's used a lot in Catholic/religious families, as is Theresa. So is Maria/Mary. If you're looking for a biblical twist, then Anya fits and is nice.

Tess- lovely, fierce, poetic sounding name (I also think D'Urberville's)
Helena- beautiful, elegant and Shakespearean (I pronounce it Heh-len-ah personally)
Jane- underused, classic, strong and romantic sounding to me (Jane Eyre)
Mariah- dislike this spelling. Maria is fine (can still pronounce it as Mah -rye -ah like in the 18th Century - like So-fye-ah instead of So-fee-ah)
Anya- fun and exotic sounding but kind of a different style to your other names (classic Anna nn Anya would fit better)

I like all your choices, so it's hard to choose the nicest (probably Maria is my least favourite) - you might also like Eve, Julia, Juliet, Lara, Lorna, Louisa or Antonia

Tess - like a lot. Not keen on Tessa
Helena - prefer Helen by far
Jane - like a lot
Mariah - ok, I also like Maria
Anya - ok but prefer Anna as it sounds stronger

Tess - lovely, I also like Tessa and would probably go with that with Tess as a shortening so she has the choice. One of the reasons I like the Welsh name Tesni is for the option to shorten it to Tess.

Helena - nice but pronunciation issues. The only one I know is Norwegian (Helayna)

Jane - pretty classic which is underused

Mariah - prefer Maria spelling but then she'd inevitably get Maree-ah.

Anya - I love this. Short, simple and pretty. I know two, an American and a Norwegian. Have always liked the name.

I would go with Anya or Tess/a.

Tess always has connotations of heftiness to me -- maybe because of the singer 'Two Ton Tess' and the bomb type called 'Ten Ton Tess' used in WWII? (Tonne? Ton? It now looks wrong whichever way I write it...)

Tess - LOVE! So cool and fresh and pretty
Helena - like it pronounced 'Helen-a' and love nickname Nell, but dislike pronounced 'Helayna'
Jane - very dull, i'd feel a bit sad for a little Jane, all I can think of is 'plain Jane'
Mariah - nooo too Carey, although Maria and Marie are okay
Anya - like it but not as much as Tess which is my favourite. I'd choose Tess for sure.

Sorry OP, not keen on any of them. Anya is the best of a bad bunch IMO. Who cares what randoms online think anyway?

Tess as in Tess of the D’Urbervilles , beautiful.
Really don’t like Mariah.

Love Tess, Helena is nice, Anya OK, Jane nice as a middle name, dislike Mariah.