Are these a bit 90s?

They are quite 90s but I still hear Chloe, Maddison especially Rosie a fair bit. Elsie is less popular than Oliver so if you still like it I don’t think that’s a reason not to use it.

From your list, Chloe and Rosie feel like a nice fit with Oliver. I really dislike Maddison.

These feel a little 90s/00s but still more current in style, with lots of E sounds:

Emily/Emma
Isabel/le (Izzie)
Hannah
Lucy
Molly/Holly
Georgia/Georgie
Grace/Gracie
Sophie
Bethany
Anna/Annabel/Annalise (Annie)
Megan (Maggie)
Amy
Harriet (Hattie)
Sarah (Sadie)
Madeleine/Madeline (Maddie)
Bethany
Phoebe
Zoe

Girls - I think Kelly and Kimberley are a bit dated but the others are absolutely fine. Chloe is my favourite.

Boys - l really like Alex on your list. Teddy and Arthur are ok.

Amber and Scarlet are 90s names that I like. I quite like Chloe.
Love Oliver.
I don't like Alfie, Archibald, Albert, etc but love Alexander.
Oliver and Daniel ❤

Your girls names are 90s yes, not necessarily a bad thing, but hard to know how they’d be viewed now by their peers. Maybe the equivalent of a late 90s/00s teen being named Tracey/Debbie/Pam?
Chloe is not that 90s tho, there are currently lots of teen Chloe’s about.

Some of your boys names are really overused. There are sooo many Alfie’s/Arthurs/Archies. Try and avoid one of those unless you really love it.

Courtney, Kimberley, Chloe…are you a fan of the kardashians?

I do like Courtney though!

Chloe, Arthur or Alexander would be my picks. Chloe is slightly 90s but still a good name (also like Phoebe).

I think Chloe or Arthur would be lovely. Both are great names and would go well with Oliver

They are really the only names I like from your lists - the rest I really dislike.

Love Courtney, and Chelsy.
Others you might like ..
Alison
Kathleen
Emily
Rebecca

Of your girl names I dislike Maddison.
Most of your boy names are not to my liking, though are not offensive.

Joseph, Luke, Arthur and Alex are handsome in a similar way to Oliver. The others you list are very trendy and not as timeless.

Some you might like..
Thomas
Scott
Tristan
David
Wallace
Edward
Ewan
Charles

Meredith
Addison
Rachael
Clarisse
Selena
Christianne
Robyn
Isabel
Juliet
Phoebe
Lauren
Sophie/Sofia
Briony
Leonie
Alexandra
Daniella

Toby
Peter
James
Jonathan
Harris
Hamish
Liam
Connor
Cooper
Christopher
Leo
Daniel

Kelly - the only Kelly’s I know are in their 40s
Rosie - Rose babes are very popular where I live
Chloe - late 90s/early 2000 babe
Maddison - love this, don’t associate with any era
Kimberley - I’d say more of 70s name , love it, haven’t heard it used for years

Axel - not keen
Alex - short fir Alexander, classic name
Teddy - every other baby and odour dog was named this five years ago
Chester - not keen on ‘surname babes’
Arthur - classic
Archie - quite popular
Alfie - not sure

Your boys names seem to have a different feel to your girls names to me.

suggestions -

Luke
Richard
Adam
Robert
Callum
Rory

Molly
Kirstin
Meredith
Amber
Jasmine
Daisy
Gemma

Nobody would bat an eyelid at any of these names in my part of London. Go for whichever you like 👍

They are quite 90s but not necessarily a problem. Kelly and Kimberly especially. I feel like most nicknames are E sound names though.

Molly/Polly/Holly
Lucy
Betsy (Elizabeth)
Ellie (Eleanor)
Nancy
Kathy (Katherine)
Darcey

Feel like Archie and Alfie are SO common atm.